SIP build on incline

[Matt Darey]

Hi guys, I intend to build a single floor frontal glazed SIP passive house inspired house on a hillside cantilevered in N Wales UK.  If anyone has done a similar cantilevered project with SIP's, please let me know.  Many thanks.  Pic attached for ref

[JohnMo]

Looks nice. See you have two supports for the balcony section, increase to four and the huge expense to cantilever vanishes.

 

Not sure how you get passivhaus energy performance with all that glazing? You are also going to need to add plenty of additional insulation to the sip to get to passivhaus standards, so somewhat defeats there advantage.

 

Although you have an overhang for shading watch out for low eastern and western sun, as it will find its way under and overheat the house, if you don't plan well.

[Iceverge]

Looks nice. Very LA hills. I double down on the overheating cautions and also the heating energy requirements for all that glazing.

 

Good windows are still 5 times worse than average walls in terms of heat loss. 

 

 

[Russell griffiths]

 thinking about this as a sip build is irrelevant, there will be so little in the way of sip construction in that design. 

50% of it will be steel and concrete, 20% glass, then do whatever you want for the remainder. 

 

I agree with others, a couple of extra columns will save you multiple of thousands in engineering design and steel and concrete. 

 

Cantilevers are nice , but not for what they cost. 

[saveasteading]

2 hours ago, Russell griffiths said:

Cantilevers are nice ,

Impressive yes. 

Add 2 columns and bring them forward and save £80k.

It would also be more 'honest' as they say.

Harnessing the forces of nature instead of challenging them.

 

On the other hand it's handy for storing left over timber, and for wildlife.

 

I know I'm a bit boring on the subject but, where does the rain go?

[Gus Potter]

I wonder if they have hidden the rainwater pipes inside the columns? The cap plate at the top would be like a polo mint.. at the bottom the pipe exists via vertical slot or something along these lines. Would be interesting to see if that works structurally, probably would as the loads are pretty low if using say a 10 inch circular hollow section.

[Matt Darey]

On 07/11/2023 at 13:18, JohnMo said:

Looks nice. See you have two supports for the balcony section, increase to four and the huge expense to cantilever vanishes.

 

Not sure how you get passivhaus energy performance with all that glazing? You are also going to need to add plenty of additional insulation to the sip to get to passivhaus standards, so somewhat defeats there advantage.

 

Although you have an overhang for shading watch out for low eastern and western sun, as it will find its way under and overheat the house, if you don't plan well.

Thanks John, I knew I'd get some invaluable comments right off the bat.  Yet to go to a structural engineer and yeh prob take your advice and save some serious £

[Matt Darey]

On 07/11/2023 at 22:07, Gus Potter said:

I wonder if they have hidden the rainwater pipes inside the columns? The cap plate at the top would be like a polo mint.. at the bottom the pipe exists via vertical slot or something along these lines. Would be interesting to see if that works structurally, probably would as the loads are pretty low if using say a 10 inch circular hollow section.

Thanks Gus, really appreciate you taking the time to think about these details.  there going to be a rainwater harvesting tank at the back taking the roof water, then need an exit for when thats full.  To keep it minimalistic, that idea of running the drainage inside the columns is definitely one I'll bring up with the architect.

[Matt Darey]

On 07/11/2023 at 21:54, saveasteading said:

Impressive yes. 

Add 2 columns and bring them forward and save £80k.

It would also be more 'honest' as they say.

Harnessing the forces of nature instead of challenging them.

 

On the other hand it's handy for storing left over timber, and for wildlife.

 

I know I'm a bit boring on the subject but, where does the rain go?

its a tiny level plot so brining it forward like this gives so much more floor space, yep rain water to consider, harversting tank at the rear and an exit to be considered, I like Gus's idea on that

[Matt Darey]

On 07/11/2023 at 13:56, Iceverge said:

Looks nice. Very LA hills. I double down on the overheating cautions and also the heating energy requirements for all that glazing.

 

Good windows are still 5 times worse than average walls in terms of heat loss. 

 

 

That glazing, being triple gonna be expensive, the view justifies it though:) Thinking of a Louvre to mitigate the overheating problems.  I'll have to make some calculations on how many windows will require shading and also the optimal overhang too.  

[Matt Darey]

On 07/11/2023 at 19:13, Russell griffiths said:

 thinking about this as a sip build is irrelevant, there will be so little in the way of sip construction in that design. 

50% of it will be steel and concrete, 20% glass, then do whatever you want for the remainder. 

 

I agree with others, a couple of extra columns will save you multiple of thousands in engineering design and steel and concrete. 

 

Cantilevers are nice , but not for what they cost. 

Dam, I was hoping to keep the Carbon footprint on this as low as possible, guess its back to the drawing board on that.

 

[saveasteading]

26 minutes ago, Matt Darey said:

I like Gus's idea on that

I saw this in action yesterday. A petrol station had tubes supporting the gantry, and the rainwater pipes disappeared inside them. I hope they were plastic all the way to the drainage system or the steel will rust.

btw the pipes were made of spiralled steel plate, like a toilet roll inner is made, but 500dia, painted red and  rather splendid.

 

[Russell griffiths]

Looking at that picture, things could be deceiving, and that design could be simplified and costs cut significantly. 

 

Imagine if all the overhanging areas were just the roof and the deck/ patio area. 

The actual house punches through the patio area and goes directly to the ground, so could sit on fairly normal foundations, then at the floor level a lightweight steel frame projects out to create the deck area, this sits on columns that go straight up to roof level and pick up the oversailing roof. 

 

It depends really on @Matt Darey budget, he didn’t seem that keen when I said it would involve lots of steel and concrete. 

[Iceverge]

3 hours ago, Matt Darey said:

Dam, I was hoping to keep the Carbon footprint on this as low as possible, guess its back to the drawing board on that.

 

 

Ah, build a passive house proper out of stuff that used to be plants. 

 

Then use an ASHP and some PV and you're punching.

[Gus Potter]

4 hours ago, Matt Darey said:

I like Gus's idea on that

Thanks for the appreciation.. but practically and on site when the pressure is on.. the sequencing of works could fry everyone's brains.. and if it "forgotten" about it could cause havoc later on.

 

Mind you this is the advantage of self building and keeping an element of control.. if you put the work in early and understand what you need to do and when then you can tackle the whacky and present it as simple to the builders.. which helps stops them adding on daft costs.

 

I can see this might suit the home automation folks on BH.. its a free duct (apart from the fabrication of the cap and notching at the base) so can you put something in it!

[Matt Darey]

On 09/11/2023 at 18:34, Russell griffiths said:

Looking at that picture, things could be deceiving, and that design could be simplified and costs cut significantly. 

 

Imagine if all the overhanging areas were just the roof and the deck/ patio area. 

The actual house punches through the patio area and goes directly to the ground, so could sit on fairly normal foundations, then at the floor level a lightweight steel frame projects out to create the deck area, this sits on columns that go straight up to roof level and pick up the oversailing roof. 

 

It depends really on @Matt Darey budget, he didn’t seem that keen when I said it would involve lots of steel and concrete. 

Thanks Russell, that would actually work with the site . There enough room to put the entire first floor footprint apart from the Balcony on solid ground. Just means less garden space which I can live with , yeh, less  concrete and steel , less co2 & less 💰

[Matt Darey]

On 09/11/2023 at 18:40, Iceverge said:

 

Ah, build a passive house proper out of stuff that used to be plants. 

 

Then use an ASHP and some PV and you're punching.

Yeh if I move the whole ground floor foot print back onto the solid ground I can use a timber frame and as suggested below more of a light weight concrete steel supporting mechanism for just the decking overhang . 

Edited November 10, 2023 by Matt Darey

[Iceverge]

On 10/11/2023 at 20:53, Matt Darey said:

Yeh if I move the whole ground floor foot print back onto the solid ground I can use a timber frame and as suggested below more of a light weight concrete steel supporting mechanism for just the decking overhang . 

 

It would save a good chunk of the budget for sure. 

 

For a truly low emission impact building be careful that your design is climate appropriate too. No reason it couldn't last 500 years if done right. In the British Isles we have scores of examples.

 

Robust water shedding is much more important in Wales than the Mediterranean for example. Consider the optimum roof angle and orientation for PV, make informed decisions about glazing. Too much will be expensive to heat and cool.