Detailed Planning & Quantity Surveyor Required For Building Quote?

roses

Hi, I posted a few weeks ago about finding a builder to build my kitchen extension.

I have had two builders round and before they can provide a quote, both are asking for:
detailed diagrams showing exact layout
materials required for building
structural beam calculations

Now when I got my loft done, the loft company did all of this for me. It is normal for me to have to go to such detail for requesting a quote for a kitchen extension?

It seems a bit much to do all of this just so the builder can then take the requirements and build exactly that. What if there is a problem with the materials used (building control) or structural beams? There is a clear lack of ownership with this method as if somthing goes wrong, one person will blame the other.

I have planning permission and a rough idea of the layout but to be honest, until I see the structural shell, I don't know where I want my cabinets, plumbing, electrics etc.

I was really hoping that a building company would provide the structural calculations & recommend the materials used (bricks, insulation etc) themselves. Is this not normal?

hanandhen

hi
if u have planning then u should have the plans for the extension so the builder could work off them for an estimate allow £800-£1000 per sq mt of floor space, how big is the extension is it single story or double?
as for calculations of the structral beams u could ask the builder to get these done then pass the cost onto u or u find someone to do them, beams will vary in price depending on how big they are
did u have an arctitect to do the plans if so they would normally put in for building regs and this will include all the materials needed to be used,including the cals for the beams
i would not let a builder specify this because if they get it wrong then it will cost u money
they dont need to know exactly where the kitchen is going as u could decide this when the structure has been built,

System

you should figure out the layout of the kitchen before you start to build it - you have to know where drains/water supply and electrics are, these things can add a lot (or a little) to the complexity so you are just asking how long is a piece of string there! - the builders should be able to work out the materials from the drawings, no point in paying someone to sit and write down the quantities if you have a proper set of drawings.
I take it there are some larger openings in the extension? normally there are standard sizes to work with but if you need a building warrant you will have to get the calculations done anyway

iamcornholio

Although any good builder can do loft conversions, there are specialist companies who do all the work on a design and build basis. But you don't tend to get many companies that do this for extension work

You could do with a good designer to draw the extension up, and if you choose one with appropriate CAD software, he could design the internal layout to your requirements and show you there and then what it will be like, and make changes to your requirements before doing the final prints for the builder to work off.

Any structural design and calculations would not normally be done by the builder, but by the designer as part of the design work. The desinger should also specify the materials.

An alternative option for you is you get a basic plan drawn up, and use what are known as "provisional sums" for the internal kitchen and services layout. With this method, you get the builder to price for a basic kitchen layout or 'x' number of units and standard worktops etc, and 'x' number of sockets. Then when the shell is up, you can look around and plan your layout, and then the builder merely adjusts the final price up or down based on how much your final layout differs from the "provisional sum" previously allowed

But you really need to engage a competent designer to draw up comprehensive plans for the builder to quote off. The more detailed the plans, the less ambiguity, and the less chance of the builder charging more for "unforeseen" work. Good plans can save you more in build costs