Advice on phasing a double side and rear extension?

[ricky2023]

Hi there, this is my first post. I'm seeking some advice on how I go about planning my home extension. I am buying a 3 bed semi which is need of a complete gut out.

I have an initial budget of approx £110k +£20k contingency

I had a builder suggest phasing the refurb+build, so I had a think and came up with the below idea. I'm speaking to an architect about it, but I'd love to get some advice and second opinions from experts on the forum that have done projects like this before.

My main questions are

• How would you phase the build, given the initial budget?
• Structurally, what do we need to consider with each phase?
• Roughly, do our budgets sound about right?

Existing floorplan:

Phase 1:

• Refurb inside (new electrics, plastering, plumbing, boiler, floor, heating, doors, windows)
• Rear extension approx 45m/sq (kitchen/diner + utility space)

Phase 2: target budget £120k

• Double side extension
• Build over existing rear extension for part double rear
• Loft - not part of design

Downstairs

Upstairs

 

[^woody^]

What's your understanding of phasing? Actually building in distinct phases, or just timescales?

Budgets don't dictate phases unless the money is only available in set stages.

A project is normally planned in the basis of need and practicality.

And don't let a builder dictate your programme, unless it's a design and build with agreed start and end dates.

 

[thomp1983]

The issue with 'phasing' or basically doing seperate extensions at different times is you need to be very on the ball with making sure that things that are done in the first stage are good enough to support the later stages or you'll blow through money redoing work.

For example any upgrades to the heating system need to factor in all future radiators and bathrooms in all the stages , ie. If you renew the gas supply inside the house make sure it supplies enough for any future gas appliances not just the current boiler and the first extension.

Make sure the consumer unit has enough ways to support all future extensions.

Think about where the plumbing and electrics are now and how they will enter and exit each of the new extensions and make provisions for it during the first part.

 

[ricky2023]

What's your understanding of phasing? Actually building in distinct phases, or just timescales?

Budgets don't dictate phases unless the money is only available in set

So the cash I have up front is £110k+£20k (not enough for the full double side, rear and loft in one go). I’d need to save for a few years to raise enough for the next phase.

so phase 1 - 2022
Phase 2 approx 2025

 

[^woody^]

Then you need to do the refurb and extension and carry out and structural works that will be necessary on the later phase so that you don't end up disturbing the completed works later.

Your plan drawer should advise on what's necessary for each phase.

Or you tailor the works, the specification, to get all the work done to a reduced standard, and then up grade/ complete works later. eg the refurb and structural shell, to a livable condition, then internal works of the loft or extension later.