Green Building Forum - renovation and extension, overall project questions Tue, 19 Dec 2023 08:30:29 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299343#Comment_299343 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299343#Comment_299343 Thu, 22 Dec 2022 16:25:44 +0000 ianh100
We want to make the property as efficient as possible so have a big wish list of technologies we hope to use but struggling to find anyone to help select the best selection on choices we have.

The current property has 2 bedrooms and 1 bathroom. brick construction with foam filled cavities. The loft space has been badly insulated with >300mm of glass on on the floor but also glass inside the tiles (never seen that before). Ventilation has been blocked and I have condensation.

We will be adding a 9m x 7.5m open plan living space and converting the current property to 3 beds and 3 baths. In addition there will be a very large garage, office, laundry room and hallway.

The new build sections have been specified with thermal blocks, 150mm of Kingspan and a 10mm cavity. Only a small amount of the existing walls will remain external so we would like to consider external insulation for these walls.

We would ideally like wet UFH, solar PV, battery storage and possibly ASHP. The current flooring is a suspended wooden floor with around 600mm cavity, below this is a concrete pad which is clean and dry. The new build areas will be beam and block so wet UFH is not an issue but we are not sure what to do in the original footprint. Should we fill the void? Should we insulate between the current joists and fit one of the lower profile UFH solutions?

I can find people who will design the UFH install for me but they don't seem to be able to advise the best construction choices for the floors or how we consider the full building choices for insulation etc. We also plan to include MVHR in all rooms, again we can find MVHR people but can't build a full project view of where best to spend the money.

I appreciate I have asked many different questions, I would really appreciate any input on specific questions but more so on how to take a full project view to get the best balance for the overall design.

Thanks in advance.]]> renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299390#Comment_299390 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299390#Comment_299390 Sat, 24 Dec 2022 20:03:54 +0000 tony
I worry about air leakage through and round the edges of beam and block floors]]> renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299391#Comment_299391 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299391#Comment_299391 Sat, 24 Dec 2022 20:05:13 +0000 tony renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299396#Comment_299396 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299396#Comment_299396 Tue, 27 Dec 2022 09:19:01 +0000 Osprey renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299397#Comment_299397 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299397#Comment_299397 Tue, 27 Dec 2022 09:47:04 +0000 philedge renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299402#Comment_299402 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299402#Comment_299402 Tue, 27 Dec 2022 16:42:58 +0000 Peter_in_Hungary Posted By: ianh100The new build sections have been specified with thermal blocks, 150mm of Kingspan and a 10mm cavity.
The make up of the new walls is not entirely clear to me. It sounds a bit like single block with EWI - but where is the 10mm cavity? and what are you going to do with a 10mm cavity?

Unless you are in a very exposed location I would go for a single block wall with EPS EWI. EPS is generally cheaper than Kingspan even after you have accounted for the additional thickness required for the equivalent U value and EPS is a bit breathable whereas Kingspan is not.

Posted By: tonyI worry about air leakage through and round the edges of beam and block floors

If you use single skin block with EWI then there is no leakage at the ends. Will there be a void under the beam and block? Why?

Over here beam and block floors are only used for first floor or where there is a cellar. Ground floors are all insulated slab with or without UFH. (Slab insulation is typically 100 grade EPS)]]> renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299418#Comment_299418 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299418#Comment_299418 Wed, 28 Dec 2022 15:03:09 +0000 jamesingram Walls, single skin 150mm medium dense recycled aggregate blocks with >200mm Graphite EPS EWI , thin coat mesh render.
same EWI can be added to existing walls.
Floor , Ground bearing slab throughout, consolidated back fill, sand blinding, >200mm EPS, >100mm concrete slab with wet UFH tied to light reinforcing mesh set mid way in slab, floated to good finish ,self level thin top coat if required
Roof >350mm cold vented loft, good detailing to tie in wall and loft insulation
Windows Triple glazed 44mm units.
MHRV , system using loft space under insulation to run pipes. fan sited in utility room cupboard.
Solar PV inroof system of new roof section if possible to save on new roof finish materials.
Consider 6+kWp of panels and 8kWh batteries , plus immersion export dump
High level of air tightness is important.

With these levels of insulation and detail it may be possible to have very little heating demand.
this would allow you to save on UFH and ASHP and just rely on a cheap plugin heater on the odd cold day (depending on location and other factors, so a risk that needs to be thought through and considered)
Perhaps a wall mounted Air to Air HP might be a good back up (significantly cheaper than a wet ASHP system)
HW would then have to be via an electric immersion , 3/4 of the
year PV could cover this.]]> renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299663#Comment_299663 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299663#Comment_299663 Mon, 16 Jan 2023 12:45:05 +0000 lngn2 renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299710#Comment_299710 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299710#Comment_299710 Tue, 17 Jan 2023 21:01:45 +0000 djh renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299741#Comment_299741 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=299741#Comment_299741 Thu, 19 Jan 2023 13:33:48 +0000 modernvictorian renovation and extension, overall project questions http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=302180#Comment_302180 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=17677&Focus=302180#Comment_302180 Wed, 28 Jun 2023 09:08:20 +0100 tony
Also can often mean lower levels of insulation - I prefer highly insulated]]>