Mr Punter

Thee are lots of people who claim a basement is cheap to build as it doubles as foundations. I do not agree with them. Excavation, retaining walls, stairs, fire risk, tanking / damp proofing, muckaway, natural light and ventilation are all issues that are simple to deal with on a 2 storey house but a PITA with a basement.

Best to check with your Water and Sewerage undertaker if there is a separate surface water sewer in the street. The preference is soakaway. Failing this they may ask for an attenuation chamber. Depends on extension size, soil type, available land etc.

I don't know why they are asking for more than one bathroom to be wheelchair accessible. I often see ground floor utilities in new build that are capable of being adapted to wet rooms. For the M4(2) option there needs to be a cat 2 bathroom on the same floor as the principal bedroom.

Just before the Brexit vote we had a firm of bricklaying contractors and the vast majority of them were voting leave because they thought the Eastern Europeans were keeping wages down. There were plenty of people and press at the time who were scathing and condescending towards them but it looks like it worked for them.

There is a vast difference between the individual items. Most differ by a factor of 2 and many far more. They look similar for the main structure. Maybe just get them to do the shell and roof to the extension and organise the rest as separate trades.

If this is a rear extension can you take a photo of the back, including the neighbour's secondary window?

I think you may be out by more than 25mm. Can you use 140mm soapbar blocks to get a 140mm (plus plaster) blockwork infill?

Wot I said

Do you normally board over doorways and cut them out after? Same for windows?

The Rangemasters I have fitted all came with a bayonet type connector for the gas.

This brings back fond memories of you installing the glass pocket door.

@nod you seem to get prices from the 1970s! No wonder you built your place so cheap.

It is quite hard to see what is going on. The door needs to sit on something solid. The sill on ours bridges between the outside brickwork and the inside screed and there is 25mm Celotex upstand between.

https://www.geberit.co.uk/products/installation-systems/geberit-duofix/ Looks good if you are doing metal stud.

Rods will go round a curve no problem. You are very unlikely to have a blockage in the pumped section. The pump will not operate more than once a day. It is like a fire hose.

Some of the blockwork looks poor as well. Lintel has not enough support and blockwork above and below the bearing looks like it has been added on. Is is taking the load from a 3 ply attic truss by the looks of things! If i were the building inspector I may want to see trusses off and that section taken down and rebuilt, although I can't really see how it is on the other side.

Some people choose to have an internal stack with a dirgo and an external vent at low level elsewhere on the drain.

Is the confusion from the AOD abbreviation on the plans? I have understood this to mean Above Ordnance Datum, which relates to sea level, so most levels I see like this are positive. I am currently looking at one where the ground floor is 81.60m AOD. Even next to a tidal river we are 4.00m AOD.

On hot days the tar can melt and get onto shoes so if your car has light carpet or you wear shoes indoors it can get everywhere.

That sounds a reasonable plan. I had Magicman repair some of ours where it was dented and the repair was far worse than the damage. Is there any coating going on top of yours or is it already finished?

No problem with the bend in the MDPE. If you put the gravity chamber in around the word "bend" it will be fine. Going to the bigger pipe will help even out the flow.

You will need to ask Building Control if that would be acceptable. You may also need to submit calcs for the timber frame.

The discharge from the pump is very strong. I would prefer to have it enter the gravity IC straight on so it does not spray around the chamber.

Have they not used truss clips? Maybe on the outside of the wall plate? Find out from the timber frame company. This is their responsibility.

They may not have foreseen the price increases. Contactors typically do not want materials hanging around on site for too long as they tend to get damaged, stolen or get in the way of works. They also typically have supplier terms of 30 days so this would also impact their cashflow. If you post up the itemised quote and the invoice we will have a bit more to go on. Best if they are anonymised.