Chalet Bungalow Extension

[W4terfall]

Hi guys, super long post but tried to give you all the info. 

 

We are at the very start of planning out what we want to do to a house we are purchasing. 

 

It’s a 1960 semi chalet bungalow. Around 120m2. I believe the side building to be original. 

 

Having looked through what is available through pd and the neighbour consultation scheme we would be hoping to put a single storey extension right the way across the rear of the property. 

 

With no certain figures at the moment due to lockdown it would end up being roughly 10 x 5m. There is a step back to the side portion of the house so unsure wether we would need to replicate the 2m step. This would mean it being 7x5 and then 3x5.

 

We are hoping that the space would become a lounge in the centre with bifolds and the 4th bedroom to the side that is stepped, with a new master being made also to the other side. (A split of 3/4/3m minus wall thickness) So no bathroom or kitchen to be incorporated as they are staying put.

 

Due to the current roof pitch I would imagine a flat roof height of 2.3m externally and 2.1 internally with a lantern in the centre of the lounge.

 

We would be almost on the boundary line of each neighbour. 

 

There are no rear man holes to contend with as they are all on the front of the property. 

 

A few things to ask. 

 

Firstly I guess is, does it look feasible or am I looking through rose tinted specs at what I would like to happen. 

 

What is judged as being the best construction for the walls of this type of structure currently? (Knowing a builder makes me want to stay with block and render, but is that still the cheaper option or is timber frame taking over)? 

 

We are in Essex. The m2 prices seem to be all over the place and understandable however we are not flamboyant in desires and pretty much like plane white walls with a bit of colour splashed about the place. Are we really looking at £2k a m2 for a finished box essentially. If so how much would people estimate to get to a wether proof shell with 1st fix in place? 

 

Any advice appreciated, good or bad. Thanks a lot for sticking with the post, Pete