House Extension

330d

I am thinking of adding a side extension to our home. It will roughly be 9 x 4.5m.

I have approached a few architects and have been quoted for £400 plan drawings and £500 building reg drawings. I believe this is reasonable?

My original idea was to get a set of drawings which then could be used for builders to quote. As what I dont want is to get as far as building regs but to find out the extension will cost over my budget.

But my architect has said the planning drawings dont have enough detail to tender. Is this normally correct? So do I need building reg drawings first?

MgComp

I haven't done this myself, but form what i understand you can ask for a rough quote from builders without any drawings, and by just taking them around your house to see what they think.

330d

MgComp said:

I haven't done this myself, but form what i understand you can ask for a rough quote from builders without any drawings, and by just taking them around your house to see what they think.

Unfortunately most I have contacted are unable to do this. 

TELLIT01

Depending on where you live in the country the price can vary greatly but you should be able to get a rough costing based purely on the square metres and whether it's a single or two storey extension.

DevilDamo

If you’re wanting rough ball park figures, a cost based on the area should suffice. If however you’re wanting more firmed up costs, then you’d need the BR drawings. If you have the BR drawings done on your initial brief and the costs are higher (which they normally are), then just submit revised drawings to Building Control which are actually within budget. It’s not a difficult process. Before you even get to BR’s, you’ll need to make sure the proposals are Planning compliant, assuming they’d need Planning of course.

It’s a bit of a chicken and egg situation but you will unfortunately have to spend some money upfront in order to get your costs.

Doozergirl

What's your budget? 

The roughest of ballparks at £1,500 a metre for a simple build is £60k.  Ours always come in at considerably more than that per metre as everyone wants massive amounts of glass - big bifold/sliding doors and rooflights.  We also go to great pains to match everything in and 'hide' the extension.  
 

TELLIT01

Doozergirl said:

What's your budget? 

The roughest of ballparks at £1,500 a metre for a simple build is £60k.  Ours always come in at considerably more than that per metre as everyone wants massive amounts of glass - big bifold/sliding doors and rooflights.  We also go to great pains to match everything in and 'hide' the extension.  
 

I blame all the home improvement programmes for the massive amounts of glass.  They look good but how often in this country do we have the opportunity to open up a bifold wall and bring the garden into the house?  I guess a room with a glass end costs considerably more to heat as well.

Sistergold

Glass does cost money in building costs and later heating up the house but the light well is priceless. Even when one does not open the bifolds you have a nice big view of the garden, and lots of sun light and when it’s hot enough yes you do open up into the garden. Love big windows and glass doors! 

Best give yourself an idea of whether to proceed or not by using the £1500 to £2000 per square meter. So 9mx4.5m= 40.5 and ~41x £2000= £82000 or ~41x £1500= ~£62000 roughly 
so there you have it roughly £62k to £82k plus or minus depending on your specifications. 

-taff

I'd love some nice big glass doors, but i always wonder how do they keep the flies out....

330d

Thank you all for the comments. 

I have spoken to Architect today and will be going ahead with planning and building reg drawings. The extension should be 'straight forward'. The house has already had a side extension and my proposal was to build on top of it to create 2 bedrooms. So no fancy glass or doors!!

ComicGeek

In which case it would be worth looking at existing foundations etc now to establish whether additional works are required to support the new storey. Otherwise that's a big unknown cost.