New Home Construction

[chiang mai]

Having finished the small house for the wife’s family I’ve started to design my own dwelling. I have several criteria that I want to try and meet and these are, 1) energy efficient 2) cool without the use of too much aircon, and 3) not overly expensive. The house will be built in the South near Krabi and the current plans show the house having a livable area of 180 square meters on two floors.

I intend to use concrete post construction with concrete floors at ground level, and preformed concrete slabs at first floor AND first floor ceiling level. The reasons for using concrete at the first floor ceiling level is to provide a strong floor in the roof void that will accommodate water treatment and supply but more of that later. The reasons for using the concrete post/slab method of construction is that it is strong and the locals are generally pretty good at that type of basic construction for shell buildings.

I also plan that the house will have a two metre balcony/walkway on all four sides at both ground and first floor level. That way the roof will overhang the living structure and provide shading for the living quarters as well as a pleasant are to “sit out”.

The roof will be be split level with an air gap some two thirds of the way up (semi Thai style) which will allow hot air in the roof void to be vented – the roof will also be insulated.

For the walls of the dwelling I intend to use 15 mm hollow concrete block on the basis that the air gap in the block will provide additional insulating benefits – I am unclear as to whether the insides of the walls should be clad with further insulating material or not.

Water supply will be a combination of roof water collection and mains supply (or possibly a well) in an outside underground storage tank with a capacity of around 85,000 liters. That tank will pump water into a 5,000 litre holding tank in the roof void. The water from the first tank will pass through a purpose bought filter system and into a second 5,000 litre holding tank which will feed domestic supply. I see the benefits of this design as being 1) only a single pump will be required for the entire supply process (unless a well is used) 2) potentially unsightly supply and filter tanks are hidden from view 3) good water pressure to the domestic supply units should be achieved.

Finally, I am exploring the available supply of K Glass or other insulating glass units but am undecided on which way to go on this currently.

Anyone see any problems or omissions thus far – I will be grateful for any inputs anyone may have.

[lannarebirth]

Having finished the small house for the wife's family I've started to design my own dwelling. I have several criteria that I want to try and meet and these are, 1) energy efficient 2) cool without the use of too much aircon, and 3) not overly expensive. The house will be built in the South near Krabi and the current plans show the house having a livable area of 180 square meters on two floors.

I intend to use concrete post construction with concrete floors at ground level, and preformed concrete slabs at first floor AND first floor ceiling level. The reasons for using concrete at the first floor ceiling level is to provide a strong floor in the roof void that will accommodate water treatment and supply but more of that later. The reasons for using the concrete post/slab method of construction is that it is strong and the locals are generally pretty good at that type of basic construction for shell buildings.

I also plan that the house will have a two metre balcony/walkway on all four sides at both ground and first floor level. That way the roof will overhang the living structure and provide shading for the living quarters as well as a pleasant are to "sit out".

The roof will be be split level with an air gap some two thirds of the way up (semi Thai style) which will allow hot air in the roof void to be vented – the roof will also be insulated.

For the walls of the dwelling I intend to use 15 mm hollow concrete block on the basis that the air gap in the block will provide additional insulating benefits – I am unclear as to whether the insides of the walls should be clad with further insulating material or not.

Water supply will be a combination of roof water collection and mains supply (or possibly a well) in an outside underground storage tank with a capacity of around 85,000 liters. That tank will pump water into a 5,000 litre holding tank in the roof void. The water from the first tank will pass through a purpose bought filter system and into a second 5,000 litre holding tank which will feed domestic supply. I see the benefits of this design as being 1) only a single pump will be required for the entire supply process (unless a well is used) 2) potentially unsightly supply and filter tanks are hidden from view 3) good water pressure to the domestic supply units should be achieved.

Finally, I am exploring the available supply of K Glass or other insulating glass units but am undecided on which way to go on this currently.

Anyone see any problems or omissions thus far – I will be grateful for any inputs anyone may have.

I'm not clear if you're going to be putting 5 metric tons of water in your attic or 10 metric tons. Either amount seems pretty weighty.

[Vansana]

I like your ideas chiang mai!

I am also planning to build a house with about he same criterias you mentioned. I am working with different plans and still cannot decide whether I go for a modern house on stilts, a split level house or a bali style house.

Right now is the "Bali style"house my favorite. Rather simple to build, on small stilts, walkway on alll 4 sides, open cathedreal ceiling....

Did you check out Q-con or Superblocks for the walls?

You have a any image/plans to post?

All the best

Vansana

[LoveDaBlues]

85,000 liter tank, why? a specific purpose?

Use superblock.

[chiang mai]

I like your ideas chiang mai!

I am also planning to build a house with about he same criterias you mentioned. I am working with different plans and still cannot decide whether I go for a modern house on stilts, a split level house or a bali style house.

Right now is the "Bali style"house my favorite. Rather simple to build, on small stilts, walkway on alll 4 sides, open cathedreal ceiling....

Did you check out Q-con or Superblocks for the walls?

You have a any image/plans to post?

All the best

Vansana

I haven't come across Q-con or Superblock and imagine they are thermal or insulating blocks?

Sorry no plans as yet, everything is in the draft planning stage so that I have firm ideas to take to an architect for detailed plans.

[chiang mai]

85,000 liter tank, why? a specific purpose?

Use superblock.

I haven't come across Superblock yet but wil check it out.

The 85,000 litre water tank is my best calculation at storing enough water from the wet season, from the roof and from other catchment areas to last a few months into the dry season without drawing on well or mains supply. I calculate we will use about 3,500 gallons a month and propose to keep the storage tank topped up in case of prolonged dry spells. Basically, if you're going to build any kind of underground storage tank you may as well build a big one rather than a small one. If you read the threads on this topic elsewhere you will see that others have had a lot of success with this kind of water storage.

[chiang mai]

Having finished the small house for the wife's family I've started to design my own dwelling. I have several criteria that I want to try and meet and these are, 1) energy efficient 2) cool without the use of too much aircon, and 3) not overly expensive. The house will be built in the South near Krabi and the current plans show the house having a livable area of 180 square meters on two floors.

I intend to use concrete post construction with concrete floors at ground level, and preformed concrete slabs at first floor AND first floor ceiling level. The reasons for using concrete at the first floor ceiling level is to provide a strong floor in the roof void that will accommodate water treatment and supply but more of that later. The reasons for using the concrete post/slab method of construction is that it is strong and the locals are generally pretty good at that type of basic construction for shell buildings.

I also plan that the house will have a two metre balcony/walkway on all four sides at both ground and first floor level. That way the roof will overhang the living structure and provide shading for the living quarters as well as a pleasant are to "sit out".

The roof will be be split level with an air gap some two thirds of the way up (semi Thai style) which will allow hot air in the roof void to be vented – the roof will also be insulated.

For the walls of the dwelling I intend to use 15 mm hollow concrete block on the basis that the air gap in the block will provide additional insulating benefits – I am unclear as to whether the insides of the walls should be clad with further insulating material or not.

Water supply will be a combination of roof water collection and mains supply (or possibly a well) in an outside underground storage tank with a capacity of around 85,000 liters. That tank will pump water into a 5,000 litre holding tank in the roof void. The water from the first tank will pass through a purpose bought filter system and into a second 5,000 litre holding tank which will feed domestic supply. I see the benefits of this design as being 1) only a single pump will be required for the entire supply process (unless a well is used) 2) potentially unsightly supply and filter tanks are hidden from view 3) good water pressure to the domestic supply units should be achieved.

Finally, I am exploring the available supply of K Glass or other insulating glass units but am undecided on which way to go on this currently.

Anyone see any problems or omissions thus far – I will be grateful for any inputs anyone may have.

I'm not clear if you're going to be putting 5 metric tons of water in your attic or 10 metric tons. Either amount seems pretty weighty.

Yes you may be right and I will need to defer to an architect when I'm ready to do final plans so that loads can be calculated. At present the concept of water storage and treatment in the roof void is simply a principle and I accept that the capacities of the storage itself may need to be adjusted based on the final design. Having recently seen a home construction using the above design I was amazed at the thickness and potential strength associated with the pre cast floor slabs and assuming the vertical posts are closely matched this may not be such a big issue.

[lingling]

I like your ideas chiang mai!

I am also planning to build a house with about he same criterias you mentioned. I am working with different plans and still cannot decide whether I go for a modern house on stilts, a split level house or a bali style house.

Right now is the "Bali style"house my favorite. Rather simple to build, on small stilts, walkway on alll 4 sides, open cathedreal ceiling....

Did you check out Q-con or Superblocks for the walls?

You have a any image/plans to post?

All the best

Vansana

I haven't come across Q-con or Superblock and imagine they are thermal or insulating blocks?

Sorry no plans as yet, everything is in the draft planning stage so that I have firm ideas to take to an architect for detailed plans.

Qcon is lightweight concrete - http://www.qcon.co.th/company_pro-e.php

Good insulation properties, good enough compression strength but very brittle so breaks easily during transport and construction. Overall I'd recommend it but make sure you don't pay a single baht until they have been offloaded intact at your construction site. Factory price is B13 per block (60x20x7.5 cm), a few baht higher when you buy from construction material suppliers.

cpac has a similar product which is a little bit cheaper.

Make sure you read the usage/installation guidelines and that the workers [somewhat] follow them. Most prefer to do it the way they do it with the standard concrete blocks, which is not qcon compatible; 1cm mortar between the blocks instead of 2mm etc.

[chiang mai]

I like your ideas chiang mai!

I am also planning to build a house with about he same criterias you mentioned. I am working with different plans and still cannot decide whether I go for a modern house on stilts, a split level house or a bali style house.

Right now is the "Bali style"house my favorite. Rather simple to build, on small stilts, walkway on alll 4 sides, open cathedreal ceiling....

Did you check out Q-con or Superblocks for the walls?

You have a any image/plans to post?

All the best

Vansana

I haven't come across Q-con or Superblock and imagine they are thermal or insulating blocks?

Sorry no plans as yet, everything is in the draft planning stage so that I have firm ideas to take to an architect for detailed plans.

Qcon is lightweight concrete - http://www.qcon.co.th/company_pro-e.php

Good insulation properties, good enough compression strength but very brittle so breaks easily during transport and construction. Overall I'd recommend it but make sure you don't pay a single baht until they have been offloaded intact at your construction site. Factory price is B13 per block (60x20x7.5 cm), a few baht higher when you buy from construction material suppliers.

cpac has a similar product which is a little bit cheaper.

Make sure you read the usage/installation guidelines and that the workers [somewhat] follow them. Most prefer to do it the way they do it with the standard concrete blocks, which is not qcon compatible; 1cm mortar between the blocks instead of 2mm etc.

Thanks for that - since the subject of Q-con and Superblock was first mentioned here I managed to check out both products on the web and one or the other definitely seems like the way to go. Thanks again for the info and the idea.

[chownah]

In the description for this topic you asked for cost effective and energy efficient....so......be advised that adding more insulation will almost always increase energy efficiency...but past a certain point the inulation is not cost effective.

A theoretic example:

Suppose you have a house with R=1 walls everywhere....meaning...for simplicity sake your house is a box with no doors or windows..only walls...and the walls are R=1. You run your aircon when the outside temp is some hot temperature and you maintain some cooler temperature inside. Lets say that in this scenerio you use xxx amount of energy to maintain the cool temp. Now....let's say you add a certain layer of foam insulation (or any other type) that adds R=1 to the existing R=1 so that now your box house has R=2 walls. This will cut your energy requirement to maintain the same cool in half....so the energy savingsrealized by one layer of insulation is 50% of x. So....now you are using half as much electricity and if you want to save half of this amount you are now using with R=2 you will have to double your insulation again. This means you will have to add 2 layers of insulation while before you only had to add 1 layer....and....you will only be be saving half of the already reduced 50% of x. So.....it now cost you twice as much for your added insulation in this second go around and you only saved half as much energy and you will only require 25% of x to maintain your cool!!! If you want to save half of the energy you are now using you must double the R value again which means you must add 4 layers additioinal of insulation and you will save half of what you were using in the previous condition (using 25% of x then) so adding this 4 additional layers of insulation only saves you 12.5% of the original energy required.

Recap:

The first layer you installed saved you 50%....you save 50% per layer.

The next two layers saved you 25%...you save 12.5% per layer.

The next 4 layers saved you 12.5%...you save about 3% per layer!!!

As you can see the cost effectiveness of insulation gets lower as more is added. If you really want to get a grip on how much insulation is cost effective and when more is not then you need to design the house with all surfaces defined for insulative value and then calculate how much heat will cross the envelope with an average heat difference....calculate how much energy will be required to expell that heat (remember to use the efficiency for whatever air con equipment you plan to use) and then use the cost per kilowatt hour to find the cost of maintaining your cool.....then you have a baseline you can compare with when you tweak the insulative values for various surfaces....it ain't easy especially considering things like which walls will have direct sunlight at which times of the day...etc.

This brings up a good point and that is designing your house and landscape to keep direct sunlight off of your walls is probably one of the most cost effective and energy efficient things you can do.

Also, I'm not sure but it really seems unlikely that double glazed windows are cost effective if they are the expensive commercial type compared with cheap single glazed windows...but I'm not sure...you could do some calcs.

The greater the temperature difference between outside and inside that you want to maintain, the greater the cost effectiveness of any insulation (or double glazed window) you use. In the northern US where in winter the difference between inside and outside temp required can easily be 30 deg C thick insulation and double glazed windows are definitely cost effective....here in Thailand the temp difference is usually 10 deg C or less and almost never over 15 deg C.....so alot of the things that make good economic sense in the northern US do not here in Thailand.

Saving energy is a good thing.....its better to use too much insulation than too little.....usually.....go to Swelter's blog and you will get a good discussion of why NO insulation might be a good solution in certain conditions.

Chownah

Edited April 28, 2007 by chownah

[chiang mai]

In the description for this topic you asked for cost effective and energy efficient....so......be advised that adding more insulation will almost always increase energy efficiency...but past a certain point the inulation is not cost effective.

A theoretic example:

Suppose you have a house with R=1 walls everywhere....meaning...for simplicity sake your house is a box with no doors or windows..only walls...and the walls are R=1. You run your aircon when the outside temp is some hot temperature and you maintain some cooler temperature inside. Lets say that in this scenerio you use xxx amount of energy to maintain the cool temp. Now....let's say you add a certain layer of foam insulation (or any other type) that adds R=1 to the existing R=1 so that now your box house has R=2 walls. This will cut your energy requirement to maintain the same cool in half....so the energy savingsrealized by one layer of insulation is 50% of x. So....now you are using half as much electricity and if you want to save half of this amount you are now using with R=2 you will have to double your insulation again. This means you will have to add 2 layers of insulation while before you only had to add 1 layer....and....you will only be be saving half of the already reduced 50% of x. So.....it now cost you twice as much for your added insulation in this second go around and you only saved half as much energy and you will only require 25% of x to maintain your cool!!! If you want to save half of the energy you are now using you must double the R value again which means you must add 4 layers additioinal of insulation and you will save half of what you were using in the previous condition (using 25% of x then) so adding this 4 additional layers of insulation only saves you 12.5% of the original energy required.

Recap:

The first layer you installed saved you 50%....you save 50% per layer.

The next two layers saved you 25%...you save 12.5% per layer.

The next 4 layers saved you 12.5%...you save about 3% per layer!!!

As you can see the cost effectiveness of insulation gets lower as more is added. If you really want to get a grip on how much insulation is cost effective and when more is not then you need to design the house with all surfaces defined for insulative value and then calculate how much heat will cross the envelope with an average heat difference....calculate how much energy will be required to expell that heat (remember to use the efficiency for whatever air con equipment you plan to use) and then use the cost per kilowatt hour to find the cost of maintaining your cool.....then you have a baseline you can compare with when you tweak the insulative values for various surfaces....it ain't easy especially considering things like which walls will have direct sunlight at which times of the day...etc.

This brings up a good point and that is designing your house and landscape to keep direct sunlight off of your walls is probably one of the most cost effective and energy efficient things you can do.

Also, I'm not sure but it really seems unlikely that double glazed windows are cost effective if they are the expensive commercial type compared with cheap single glazed windows...but I'm not sure...you could do some calcs.

The greater the temperature difference between outside and inside that you want to maintain, the greater the cost effectiveness of any insulation (or double glazed window) you use. In the northern US where in winter the difference between inside and outside temp required can easily be 30 deg C thick insulation and double glazed windows are definitely cost effective....here in Thailand the temp difference is usually 10 deg C or less and almost never over 15 deg C.....so alot of the things that make good economic sense in the northern US do not here in Thailand.

Saving energy is a good thing.....its better to use too much insulation than too little.....usually.....go to Swelter's blog and you will get a good discussion of why NO insulation might be a good solution in certain conditions.

Chownah

As always, a very complete response from Chownah - thank you. But this raises an interesting issue when you say "the greater the temperature difference between outside and inside that you want to maintain, the greater the cost effectiveness of any insulation (or double glazed window) you use". As a layman in these matters it seems there is a difference between convected and radiated heat and that different design aspects of construction must be employed to tackle each separately and jointly.

For example, the first line of defense against radiated heat must be the position of the house relative to direct sunlight, shading of the walls and roof and then insulation whereas the only defense against convected heat is insulation and airflow. Additionally, heat transfer works in two directions, external heat transfer into a house and internal cooled air loss to the outside.

The radiated heat effect of direct sunlight on a roof in southern Thailand should be similar to that in the southern US hence the preventative measures should be similarly successful and the cost effectiveness identical? Similarly, the use of K glass or good quality reflective galss to deflect direct sunlight heat transfer should be identically beneficial?

[chownah]

As always, a very complete response from Chownah - thank you. But this raises an interesting issue when you say "the greater the temperature difference between outside and inside that you want to maintain, the greater the cost effectiveness of any insulation (or double glazed window) you use". As a layman in these matters it seems there is a difference between convected and radiated heat and that different design aspects of construction must be employed to tackle each separately and jointly.

For example, the first line of defense against radiated heat must be the position of the house relative to direct sunlight, shading of the walls and roof and then insulation whereas the only defense against convected heat is insulation and airflow. Additionally, heat transfer works in two directions, external heat transfer into a house and internal cooled air loss to the outside.

The radiated heat effect of direct sunlight on a roof in southern Thailand should be similar to that in the southern US hence the preventative measures should be similarly successful and the cost effectiveness identical? Similarly, the use of K glass or good quality reflective galss to deflect direct sunlight heat transfer should be identically beneficial?

My post was primarily meant to convey the principle that when thinking about using insulation it is good to keep in mind that using more is not always cost effective. I am personally in favor of people using more insulation since saving energy is a beneficial thing for people and the environment....but....I do think that those who are concerned about cost effectiveness should be made aware that while adding extra insulation maybe benefit people and the environment it might not be cost effective. An example you might want to try is to get some insulation values and prices on single, double, and triple glazed windows and then calculate the difference in energy transfer and the cost savings and see what is cost effective and what is not. As to direct sunlight on windows...rather than use special heat reflective glass I would recommend shade but of course shade is not always possible....you could run calcs on the special reflective glass and see how cost effective they are too. Other options are to reduce the window size and use of curtains or shutters. The windows on my house have no glass, only wooden shutters. We open the windows that don't have direct sunlight on them at that time of the day...actually the sun only shines on our windows in early morning and late afternoon since we have 1.5 metre overhang (or greater) everywhere. I don't need glass because I don't need aircon....I don't need aircon becaue I sited my house well, meaning I live in northern Thailand where aircon is not really necessary.

My comparison was with a home in northern US where the insulation is designed to be effective for winter heating conditions and not summer cooling so heat on the roof would be considered beneficial (at least theoretically while in practice it is ignored) and reflecting heat from a window would be considered a negative (although again this is theoretic and in practice would be ignored).

Chownah

Edited April 29, 2007 by chownah