Advice on what to budget for when planning a house extension...

[ilikeyoursleeves]

We are planning our house extension for this summer and are currently in talks with an architect. I am trying to think ahead and do a budget sheet with projected costs for everything but I'm not sure what to include!

So far I have:

-architect
-planning / building regs costs
-builders
-plasterer
-electrician
-plumber for new radiators, boiler, installing ensuite & downstairs loo
-new bathroom & loo sanitaryware
-joiner for new doors and floors
-painter for external house painting
-new decking
-new fence

Ummmmmm....what else should I include?

Thanks for that advice ihearthuckabees, it's good to hear from those who've been there done that! I'm wondering actually if we could go without the washing machine for a while but given I do a load every day and we live nowhere near a laundrette, I doubt it...

There's just so much prep involved, I'm currently trying to find out how we move the elec meter & fuse box etc... The joys!

ilikeyoursleeves - we will be doing similar to you knocking through corridor which is currently the en-suite bathroom to our room and the cupboards. Plan is a wraparound extension to one side and the back of the house. Downstairs will be a utility room and a playroom with a dining area. The current dining area bit of the lounge will be blocked off and become part of the kitchen. Upstairs a new master bedroom with new en-suite and the box room extended.

Now the REALLY annoying part is the way the house sits on it's plot, if you can imagine the garden as three thirds the house sits on the last third with two thirds garden at one side, now the annoying thing is this is right up against the neighbours boundary so chances are we wouldn't get permission for an extension that way as it's only a driveway wide then less than a metre then their house so it would look very squashed against their house. If we did go this way it would be a whole lot easier as access would be through the hall upstairs where there is a window anyway and the side door so no big knock throughs. Going through the other side where there is a lot more garden means creating a corridor and creating another en-suite. Does that make sense?

We plan to instruct the builders that the outside will be done first leaving the knock through to the end. Also we will have two bathrooms untouched and the DDs bedroom. We can put DD3 in with the other two for a few weeks. The washing machine will not move until the utility room is up and running and we will put the dishwasher in it's place. We can use the front door for in and outs as the front of the house isn't being affected.

I'm due May this year and haven't even spoken to an architect yet so imagine planning will take at least 6 months.