Hey Folks

[JayWhite]

Wifey and I are mid 50's and looking to self build our next (and thus last) home. Currently live in Somerset, but looking to move near to York in a year or 2, thinking SIPS would give us the flexibility to go with a bespoke, efficient design, hoping about £300k including plot with approx 1000 Sq Ft home.

[JohnMo]

Hi welcome.

1000 ft2 or 93m2. Compact house. Are you planning to actually build yourself or get a contractor in, to do the work?

 

SIP are good in principle, but you really need to add further insulation to get them to perform well. Once design on paper there is really zero flexibility.  I would work with a design the local work force use every day - timber frame built on site, cellulose filled, or block and brick - deep cavity then full with poly beads. Go to town on good insulation and airtightness, and then use the smallest heat pump you can get,with under floor heating on the ground floor only to heat.

[LSB]

welcome and good luck finding the elusive plot and design

 

[JayWhite]

10 hours ago, JohnMo said:

Thanks for the welcome LSB & the info John.

We thought SIPS with a decent depth were plenty insulated?

 

We're in a 2016 new build at present, and 2 beds will be fine for our retirement, hence about half our current size home. Actual self building isn't the plan, but never say never 😂

[JohnMo]

8 hours ago, JayWhite said:

Actual self building isn't the plan, but never say never

That was never my plan, but couldn't get what I wanted without doing myself, so took a work break for a couple years.

 

When assessing build method, you to consider two things, thermal loss or U value and how quickly the house heats and cools or decremental decay. Example assuming same U value. A lightweight structure (use a cube) will respond quickly to heat input (sip for example) as there is only a 18mm of wood to heat and the air inside. Now build the same cube in block work, you now have to heat the air and block work to get the air space warm. Sounds bad but...

 

Once up to temperature the block work remains so for hours or days, acting like a big storage heater. The sip only keeps a small reserve of energy in the wood, so the temp will drop quicker.  Now add a window and look at the summer. SIP heats quickly, but block work doesn't, the air will heat up, but the block work draw that heat in to even out out the temp quicker.

 

It a juggling act to get things right.

 

Cellulose insulation is wood fibre, so quite dense also hence mentioning earlier.