Do I need a quantity surveyor for my extension?

[AlohaMama]

We've employed an architect to design a single story extension for us, it involves rebuilding the garage, kitchen, making a new playroom/den, it's all quite bespoke and modern (that is to say it's not a straightforward brick built square extension). We are at the stage of getting the architect to do the detailed building plans and she's asking if we want a quantity surveyor. Do we need one? I'm getting a bit confused as to who does what. We are quite precautionary and don't want to end up with a project with spiraling costs, plus we are too busy to go through everything ourselves wiht a fine tooth comb, so would a QS help with that? But then we don't want to be paying for something we don't need. Has anyone ever used one for their extension or just for major Developments?

They are used for bigger builds generally but, if you aren't planning to project manage your extension then you could ask a QS to price it up and oversee it for you as well to make it worthwhile. Architects are notoriously poor at keeping to a budget and, for something that has lots of bespoke detailing, you may want to tie down costs before putting it out to tender. In theory, a QS, like a decent accountant, should save you the cost of his/her fee. If you're risk averse then it would be a belt-and-braces approach.

Yes it's worth it if you want to save money with some tweaks to the design, especially if the architect doesn't have a good idea of costs, but if you're not going to change it anyway then just skip straight to tendering your project.

It sounds to me like your architect may not be entirely confident costing their designs. How fixed is the budget? Do you have leeway (I'm guessing as it sounds you've gone for something a bit special). it might be worth looking for a combined QS/pm service. Who is going to pm otherwise?

Thanks for the good points. I actually am not sure who is going to PM. I suppose in theory the building contractor would PM and then liaise directly with me/DH, though the thought of that with 3 young kids seems a bit overwhelming. We gave our architect a vague budget at the beginning, but I have never really heard her mentioning costs so I'm not sure if she does have a good idea of the cost of her proposal or not. I don't think we'll have that much leeway in our budget, I'm nervous of ending up with a house where we spend more than it's market value, though in our area a lot of the properties are quite individual so it's hard to tell. I think I need to go back to the architect and get more of an idea from her and then talk to the QS as well. I guess if their fee is not astronomical then it probably would be worth it. The thought of this extension has me stressed already and we're only at the planning stages, God help me when we get to the actual build!!!

The actual build is fine until they come inside. They were basically in the garden and up scaffolding for the first couple of months. We added some moving of internal structural walls and demolishing the chimneys that go through 4 rooms to the work, and once they started that we only have the smallest bedroom usable! Also the dust is incredible! If you have kids then move out while the internal work is going on!