Mr Punter

If you are getting a main contractor to build this, you will need between £300k and £500k all in. If you do lots yourselves you could come in under £200k.

With mineral wool batts the wall ties are normally placed every 2 block courses, except for near openings where they are every block. He may be going for pushing the batts over the wall ties before building the outer leaf, but it is not the normal way to do it. Ask the Building Inspector to have a look and see what they say. Like @Spinny spotted, the location and scaffold look rather bizarre.

You need to play this from where you are and not look to assign blame. Is there any way the design of the window could be modified to comply with Building Regs? If you post up a floor plan you may get some useful suggestions.

This does not sound like a planning issue. Planning do not deal with ownership or boundary disputes. The blurb in the consent relating to Party Wall Awards is just an advisory note.

I am afraid this will be a legal matter. Your buildings insurance may cover the cost of this. If they have built over your land it is trespass. Send them a letter explaining that it is not acceptable.

It would need a clear opening width min 450mm, which is a lot for an oriel window. Can't you have the main part opening to comply?

Any water in the cavity low down will go down to the foundations and drain away.

Before you talk to your neighbour, work out what you are after. Let them see the wall damage and let them know that you think it may be due to their tree. If all goes well you could suggest that the trees are removed. You will need to listen to what they say and gauge their response. If they are hostile, just be polite and seek further advice.

I am no expert. I let the assessor know what the planning condition was and they did the SAP calcs to suit. The SAP should have Target Carbon Dioxide Emission Rate (TER) and Dwelling Carbon Dioxide Emission Rate (DER). I think your DER will need to be at least 10% less than the TER.

I don't understand why you need a 6 x 2 to make up 5-10mm? Neither does the cat.

Given the low first floor window cills you are probably going to end up with a flat roof. You could build your roof up higher than your neighbour, putting the insulation on top of the decking. If your neighbour wanted to do theirs at the same time it may work well, but not essential.

Willows are very high water users and if you are on shrinkable clay soil it can dry out and cause the foundations and walls to move and crack. Talk to your neighbour and perhaps look at getting legal advice.

Stairbox and a chippie to fit it.

I am building some new flats and have installed DMEV fans, which, together with trickle vents and wall vents will provide ventilation. I am about to get an air tightness test. The design stage SAP is stating 4.0 design value for air permeability. What if the testing shows 2.0 or 10.0?

Just have normal weeps above the cavity trays over lintels. I don't know why you need them at low level.

From the photos that was seriously poor. I think that @ProDave has Rationel and is in Scotland. I have had IdealCombi and Velfac, but I think some of the Velfac front doors are Rationel. All part of Dovista.

Take it up with the architect and get them to update the drawings so it complies. Unless it is radically different you may not even need to consult the Planning Dept.

I have used IKEA PAX wardrobes and they have stood up to 2 house moves. Good value and they look fine. I am sure they could be butchered to fit.

Regarding the gutter, if leaves and debris are allowed to build up there will be an issue, no matter how big the upstand, especially as this is not an external gutter. Do you have a regime to inspect and clear the debris? I had issues with Velux and a zinc roof, partly caused by the architect specifying 2 rooflights for which we did not have correct planning that we subsequently had to change and bodge with inevitable leaking. A right PITA. None of this should stop you cracking on with the rest of the build though.

Zinc roofing has become fashionable but decent zinc roofers are few and far between. With rooflights, you often need to solder. I would stick with what you have, get the facias, flashings and gutters on and the rest of the outside complete with scaffold away before the end of summer. Get a new zinc roofing contractor and get your windows and doors ordered and fitted.

Well done for finding a solution. I was surprised that the material cost is less than double sand cement. Let us know how you get on.

The L shape is loads better. The original plans based on a rectangle made no sense for the shape of the site. You can modify the L shape to suit the space you need. Sensible to build min 1.0m from boundaries. You need some decent floor plans developed from this. Don't get too hung up on the garage.

Could be a durgo valve stuck. It is not easy to work out where a smell is coming from. Does the soil system hold an air test as per building regs?

The principal of building a house is already agreed. What was on the outline application? They normally have some sort of drawing, so they could see what was being asked for in terms of no of storeys and bedrooms and proximity to boundaries. Lose the porch if it upsets them. Just do a reserved matters application and don't make it controversial or flash looking. I would aim for about 1400ft2. Have a look at

If the red line is the boundary you would need to get an easement from the neighbour to allow fascia and gutter overhang. You may do better with an l shape on both floors by going further back for part. +1 Allow for wider external walls. More storage, less glass.