ProDave

And the corresponding downstairs layout see we can see what any upstairs walls can transfer load to.

And where in those views does your SE think a steel is needed?

I am surprised BC passed it without trickle ventilators or mvhr.

I am very surprised that if you have all the "normal" holes in a building as listed above for individual extraction and trickle vents that he achieved an air test of less than 3. Surely it would be easy to open a couple of windows a crack just to get a worse air test than make permanent unwanted holes.

MVHR is NOT all about air tightness of a house, at least not just about how air tight you can make the fabric of the building. If i take the example of my last house, my first self build. I don't believe the basic fabric was leaky. But because it did NOT have mvhr, instead it had: Kitchen cooker hood exhausting through a 100mm hole. Utility room extract fan, venting through a 100mm hole. 4 bathrooms, each with it's own extract fan, exiting through a 100mm hole. A stove that drew it's combustion air from the room, and for that it had an air inlet vent built into the hearth do admit outside air into the room directly behind the stove. and because it was not room sealed, the stove flue effectively was vented to the room. We also had a standard letterbox in the front door, a cat flap, and every window had a trickle ventilator which even when "shut" I doubt were particularly air tight. That is what a "standard" house has as a collection of big holes to let air in and out uncontrolled. Fit mvhr and we have NONE of those. So regardless of what air tightness test you get, simply eliminating those collection of huge holes to be replaced by one inlet and one outlet and an mvhr system is bound to be a big improvement. Of course because everything was thought about this time, the WBS is room sealed drawing all it's combustion air directly from outside.

5kW will be plenty. Almost certainly way more than you need for heating and cooling the building and adequate for heating a 300L water tank. I and many others have that size of ASHP for heating a whole house.

To save others pondering whether to open an unknown 28MB file, here is a shrunk version. Us, last weekend:

Doing really well to be under £1K per square metre.

We got all ours mail order from Boston Seeds.

This is a real thing. My BIL suffers from it. He went for a walk up a hill near the sea, fine on the way up, turned around to look out to sea. The land sloping gently downwards to the sea gave him an attack. He had to crawl down the hill on all fours. It must run in the family. I took his 2 children on a hill walk in Wales, we got to a narrow ridge between 2 peaks, the stuff that for me is the highlight of the walk. The daughter freaked out and we had to find a different way down to avoid it. I guess if this is a problem for you, don't design your house with a galleried landing with glass balustrades? design it with stairs enclosed both sides by a wall and opening to an enclosed landing.

I would just heat and bend the connecting bit of pipe for that. Alternative off the ball idea. 50mm SW coupler. 50mm to 32mm reducer Note the reducer is offset. SW one in one way up, the other in the other way up. That gives you a straight coupling with about 30mm offset.

Show the specific problem you are trying to solve with full dimensions.

You need to take some bricks off and excavate in an archaeological fashion to determine at what level the ground has sunk. It could be the aco drain is leaking and the top layer of sand has washed away, or it could be something deep down that has collapsed like previously made up ground, a collapsed drain, a leaking water pipe or just about anything else.

Just a rough outline of where the house would go. ARM application went to public consultation just like any other but this time with full details.

Approval of Reserved Matters was correct, that is exactly what we did following outline permission.

Ask them to quote you the exact wording of the policy that limits the side extension to 3.1 metres. While waiting for an answer have a walk around your area and find any side extension >3.1 metres that has been allowed and see if you can track down it's planning application.

Get a formal application in. Then you will get a grown up on the job who knows what they are talking about.

Are you sure? Using the spirit stove on our boat at the weekend, with the main hatch shut but front hatch open a crack and rear ventilator open. it set off the CO alarm. I am happier that the WBS at home takes it's air directly from outside and all the products of combustion go up the flue, not into the house.

+1 Something does not sound right at all.

If you have limits on your local transformer and are concerned they may make you pay for an upgrade, ask them what IS available without upgrade. In my case i was offered a 12KVA supply which has proved totally adequate. More realistic appliance estimates Fan oven 2kW ALL lights on in the house at the same time 175W (all LED) 5kW heat pump max 2kW electricity consumption Immersion heater 3kW rarely used but auutomatically soaks up surplus solar PV Washing machine 3kW only when heating water, much lower at other times. No bit appliances like electric showers so it is easy to see why 12KVA is enough for us.

Had them in several rentals and now in the present house, never had a problem as long as you use a GOOD make. Mine are all multipanel. I was at a rental the other day where the top coating was starting to flake off, I don't know what make they were unfortunately so I can't tell you which to avoid.

While you are at it, create an access hatch to each eaves space, e.g. a removeable back to your built in bookcase.

We had a raised deck and wind out canopy from the wall at our previous house, installed there 20 years ago without PP. I guess I just "got away with it"? So if your deck and canopy were a few mm gap between it and the house, and it complied with the permitted development rules for a garden building would it comply? Unless you have vindictive nosy neighbours I would just do it and take the flack if any came.

11 metres end to end of the house, but not herringone, just wide planks.

Our engineered woof floor runs continuously through kitchen / dining, hallway, and living room with expansion gaps all the way round under skirting as one continuous run. In the hall it abuts the tiled entrance area with a flush tight fit with no problems.