Building an extension with SIPs

[masamune]

I am looking at building a rear extension for a 3 bed semi and my architect proposed an interesting design going a bit beyond the standard box. He also suggested we can reduce the cost by building with SIPs.

A few weeks ago I had no clue about SIPs, I looked up a couple of threads but would like to find out more on the practical aspects of building an extension and the current products on the market.

Some concerns that I have at the moment:

- fire, damp protection, potential issues if the material is compromised i.e from damage or damp
- structural limitations
- does it work well if mixed e.g connected to a brick house
- planning well in advance, I read SIP engineer plans need great accuracy and wiring can be a pain
- exterior cladding choices, different types of SIPs panel and quality
- insulation, how does it behave in the summer e.g can it get too hot?
- potential effect on insurance, future sale of the property
- any future issues, maintenance

Is it worth approaching a SIPs construction company for an estimate?

Please add any thoughts or feedback if you have experience with a SIPs extension.

Thanks in advance!

 

[tony1851]

Far from being cheaper, you will increase the cost using SIPs.

 

[^woody^]

There is also no flexibility.

Your architect probably suggested sips because he then does not need to do the design work, and he dodges the design risk and responsibility. But he will charge you for it.

 

[masamune]

Far from being cheaper, you will increase the cost using SIPs.

Can you elaborate please?

 

[masamune]

1.There is also no flexibility.

2. Your architect probably suggested sips because he then does not need to do the design work.

Can you elaborate 1 + 2 please?

 

[tony1851]

Far from being cheaper, you will increase the cost using SIPs.

Can you elaborate please?

Most builders working in the area of small domestic extensions are used to building in traditional brick, block and tile. They are unlikely to
know the techniques for building with non-traditional methods, so that will seriously limit the choice of builder, and hence increase the price.
It is surprising that your 'architect' has suggested such an approach.

SIPs may work for larger-scale new housing projects where time is money, but not for small domestic extensions. And, as above, they are inflexible.

The best way to prove this for yourself is to get your architect to draw construction plans (not the simple line-drawings you get for the planning application drawings) using SIPs, then invite a few local builders to give a price. Then when no builder gets back to you, post here for further advice.