My college project (just started) on Low Carbon House

10100

i hope its ok to post this sort of post in this forum.

im hoping for comments, or how else do you learn (i must admitt im nervous im gonna get slated lol) :)

we were given at college the task to draw a house is AutoCAD *pfff* i used Revit.

we were given the dimensions for the house (we all have the same foot print to work to) and over the course we have to draw the house and design it etc.

i jumped in and did mine in just over a day lol.

it has the concept of a water storage under the house (which will always be at a residual temp due to the house and the ground temp)

this is then used to either cool the house via being pumped through under floor heating, or the solar panels heat the water and heat the house. (also have a secondary air source heat pump)

i did a quick SAP and it came out as a DER of -0.08 :shamed: (but im a SAP novice so im sure this is incorrect!)

of course this is my first draft so it will under go changes, and im very welcome to comments on improvements/problems.

the basic construction is a lime rendered solid 150mm thermalite wall with 90mm celotex achieving 0.18w/mk - the roof and floor achieve the same u-value to.
windows are nordan ntech averaging 0.7w/mk.

*please note this is a college project! so be kind.*
i shall be going more in depth with the design shortly and look forward to recommendations!

http://bimthere.info/college/FE%20-%20College%20-%20800.jpg
http://bimthere.info/college/RE%20-%20College%20-%20800.jpg
http://bimthere.info/college/SE%20-%20College%20-%20800.jpg
http://bimthere.info/college/SE2%20-%20College%20-%20800.jpg
http://bimthere.info/college/GFP%20-%20College%20-%20800.jpg
http://bimthere.info/college/FFP%20-%20College%20-%20800.jpg
http://bimthere.info/college/SFP%20-%20College%20-%20800.jpg
http://bimthere.info/college/S1%20-%20College%20-%20800.jpg
http://bimthere.info/college/S2%20-%20College%20-%20800.jpg
http://bimthere.info/college/SE3%20-%20College%20-%20800.jpg

Matt

10100 - its a catchy name!

Which way is the building orientated?
What Infiltration rate did you assume?

tony

Looks good! Window shading ledges need to be wider. Thermal bridging at eves? Shape of house is not the most efficient more exposed walls than ideal.

Like the water tank idea -- please explain more --

I would never build anything from aerated concrete blocks they crack and move arround too much.

Gotanewlife

Have a look at these maybe for some inspiration:

http://web.axilar.net/LarenCorie/PSBD1.htm

The sites not finished (and doesn't look like it will ever be) but might spark something. Also chaps comments on shadding/overhangs are the most sense I have found on the 'net.

CWatters

Swap that bath for a more energy efficient shower?

The windows look a bit small generally but I understand the reason why.

Not a green issue but...Some of the bedroom doors open the wrong way from a privacy point of view (eg when door slightly open you see the bed rather than a wall).

jon

Think about incorporating your founds into the water storage system. You will need very food vapour control and insulation to get the balance right.

Do you google a lot... is this where 10100 comes from?

ali.gill

how about incorporating a basement hence pushing the hydraulic thermal storage deeper into the ground away from diurnal temperatue change and negating the need for perimeter insulation (to storage vessel)

Paul in Montreal

Posted By: CWattersSwap that bath for a more energy efficient shower?

Nothing wrong with a bath. Leave the water to get cold when you get out and you recover most of the heat that went into heating it (assuming you don't have a humidity problem).

Not sure you'd want the outdoor unit of your ASHP in a location where it's impossible to service - much better on the ground if you can do it - plus it would be away from the bedroom windows.

Any chance of larger pictures so we can see the dimensions?

Paul in Montreal.

TheDoctor

What course is this?

Architectural Technologist / Technician?
something else?


solar panels - put them together rather than as separates. Make them integral to the roof, rather than add-ons, and eliminate all those nasty details where water gets in.

I'd be worried that you have taken the design too far on day 1.
Having furniture layouts etc all drawn up in plan section and elevation make it harder for the design to evolve.
Consider being flexible until you have really bottomed out your construction type, plan form etc.

A re-draw to add 150mm to the walls (for example) is more of a pain when you have a complete set of drawings.

start loose and then tighten up.


wasted space in the lower loft?
perhaps drop this element and use the roof-space

joekozelka

I looked at the U-Values of walls with normal bricks and block with a 100mm cavity. I first used 50 mm of Extruded polyurethane in the cavity. Next I tried using the thermalite block and made it 150 mm thick to see the difference in the U-Value. The Extra 50 mm thickness of thermalite block made little difference. Adding Extra 25 mm insulation did make a big difference. I spoke to bricklayers who tell me that thermalite blocks are not much good at fixing for shelving and the like. I have seen buildings these days with the cavities full of insulation. I am not sure that is a good solution as it does away with the cavity. Are they suggesting that cavities are not needed at all? I would make the cavity larger thus accommodating more insulation. Alternatively one could place an extra 25 mm of insulation on the inside of the wall under the plasterboard. Make sure there is a good vapour barrier to reduce vapour pressure as well as the risk of intrinsecus condensation.
Other suggestions might include solar hot water panels. Free hot water can only be a good thing perhaps combined with under floor heating. Under floor heating makes for a more comfortable environment and operates at a lower temperature than radiators, saving 30% energy. A sunny day would give you hot water and heat your house for free.
People studying for their masters in sustainability seem to be concentration on the amount of energy that falls on a building or sunshine. The calculation is based on the amount of energy that falls on the building and the amount that is retained. You might look at solar gain and thermal mass as a solution. And do not forget to make full use of natural light.

Joiner

Hopefully, 10100 will have done the sensible thing and read through relevent threads on here.

Have you Joe?

MikeRumney

10100 ... couldn't open your links I'm afraid so working blind but wanted to mention that the underground water store could present bacterial and fungal problems unless you've worked in good access.

You might want to look at "inter-seasonal" heat storage or "AGS" (Annualised Geo-solar) which involves storing heat in Spring/Summer for release Autumn/Winter.
The storage medium is then the soil, rock or whatever is in the existing ground.
This is done by making the heat travel anything from 3 to 6 metres, depending on ground type and conditions, before it reaches the floor slab ... Insulation the foundations, &/or the ground around the building can play a part ... should be some threads on here.

Have you been given the option to orientate your build? Lots to be gained from getting the angles right ... you'd probably get some brownie points for specifying this dependant on global position as well.

Is the module supposed to include the building process?
You might want to specify ways of reducing things that contribute to the "embodied energy" of the construction ... like carting waste away from the site, sourcing materials and products from abroad, looking at how much energy is required to make an insulant relative to its ability to save energy etc etc.

wookey

Links don't work for me either, so I can't say anything very useful about the design, except that you don't say what the criteria are. Do you need to comply to particular design standards (UK building regs? Code something? AECB silver? passivhaus?). Is the objective to build to certain costs or do whatever you like within the given footprint?

If it was me I'd turn the insulation up, especially in the roof, to somewhere more like 0.1 W/mK, but maybe your 0.18 makes sense given the constraints.

Yes you are welcome to ask questions like this here - as you can tell from the feedback, but we are a bit quaint and old-fashioned here and would like to see some capital letters at the start of sentences :-)

Joiner

why?

SteamyTea

Why don't they links open (look at the age of the original post, they will be another unemployed graduate by now).
Or why start a sentence with a capital letter. One good reason is for partially sighted readers to identify the start of a sentence, another is good practice (like looking right, left and right again when crossing a road) and finally because it makes a text stand out from the rest (except on the GBF, where we obey all laws of English and Thermodynamics).

Joiner

Dangerous ground, ST.:devil: Spelling and typos could be next.:wink:

SteamyTea

I make many of both and numbers are easily confused. :bigsmile:

MikeRumney

Posted By: SteamyTeaWhy don't they links open (look at the age of the original post, they will be another unemployed graduate by now).

can't believe I didn't clock the date ... how come it popped up again?

biffvernon

Here's a challenge,10100: design a house that involves lower carbon emissions in both construction and use than my one http://www.faeriehouse.tithefarm.biz/

SteamyTea

Biff
Do you have figures for the embodied energy, heat load, m^2 and volume of your faerie house?

biffvernon

No, Faeries find such things quite tiresome.

Do you know what the embodied energy in a straw bale or a wooden pole is? Does it matter? Most of the energy slid down sunbeams.

The floor is seven good paces across and the height twice that of a tall man in the centre sloping to one man's height at the edge. Go calculate.

I've no idea of heat load but the Faerie has a fine duck down duvet and says she's as snug as a bug in a rug.

SteamyTea

Shall get back to you Biff after I have had a word with the Piskeys who will probably have to have a word with the Knockers.

DamonHD

.