What needs to be decided before first fix?

This is the point where it really matters that you've gone over everything and planned thoroughly.

A lot of the problems people run into during the renovation itself come from not knowing what to have planned up front before 'the work' happens. So on top of issues that you couldn't have predicted (hello, rotten joists), you're also playing defence on a bunch of decisions you should have made earlier.

First fix is when everything that will be hidden is installed:

• Plumbing and heating pipework
• Electrical cables and back boxes
• Any ventilation ducting

After this, walls and floors are closed up.

Start by prioritising amongst the lists of ideas you have for the space. Before getting into specifics, you need a clear idea of what the space actually needs to do.

• Who is using the space?
• How does it need to function day to day?
• What are the priorities?

A simple way to approach this is to split your thinking into:

• Wants (nice to have)
• Needs (must have)

Once you prioritise these lists, it becomes much easier to make the decisions that follow.

You need to know exactly where everything is going:

• Bathroom fixtures (toilet, basin, shower, bath)
• Kitchen units / built-in furniture
• Appliances
• Lighting
• Sockets and switches
• Anything else wall mounted or recessed...!

This is why creating a to-scale plan is so useful early on.

Start by marking:

• The soil pipe location (where it exits the room)
• Windows and doors
• Structural elements like pipe columns or attic hatches
• Wall types (solid or stud)
• Floor construction (concrete or suspended timber)

These determine what can realistically move and what is best left where it is.

Anything involving water needs to be fixed now:

• Toilets, basins, showers and baths
• Radiators and towel rails
• Appliance connections

Moving plumbing is one of the biggest cost drivers in a renovation, especially toilets! Read more on why moving the toilet is a big decision.

You need to finalise:

• Socket positions
• Light switch locations
• Lighting layout
• Any other fixed electrics e.g. extractor fans, wired sensors and alarms

Need help? Start with where you want the light switches, where to put plug sockets in a bedroom, how many lamps in a living room and where to put plug sockets in a kitchen.

It's tempting to choose these later, but many of them affect what needs to go inside the walls.

For example:

• Wall mounted taps need pipework inside the wall
• Concealed showers need space for valves
• Wall hung toilets need frames and cistern space

These choices often require building out walls or allowing extra space.

Need help? Start with what all the things mean when you're choosing a shower, which bathroom taps should I choose. and the differences between the different types of toilets.

These are the ones that tend to get forgotten until the builders are on site:

Commonly missed items

• Mirror lighting positions
• Shower controls and niches
• Extractor fan placement
• Data / ethernet points
• External lighting
• Towel rails and hooks
• Toilet roll holders
• Shower screens
• Wall hung vanities
• Shelves and cabinets

Depending on what you have planned, these usually mean adding timber supports (often called noggins) between studs during first fix.

Not everything has to have timber behind it but for anything heavy, used frequently or safety-critical (let's avoid a mirrored cabinet falling off a wall) you want these things in your plan to ensure everything has proper support!

If you don't plan this all in early, you can end up limited on where things can go later, or relying on weaker fixings. This is especially relevant with stud walls, where there could be nothing solid behind the plasterboard where you need it.

If it has a component that goes inside a wall, floor or ceiling, it needs to be decided before first fix.

Even if you are keeping things "in the same place", changes in what you choose can still affect first fix.

For example:

• Swapping a pedestal basin for a wall hung basin
• Changing to wall mounted taps
• Choosing a different type of shower valve
• Choosing a different style of toilet

All of these can mean moving pipework or changing wall construction.

First fix is not the time to be deciding things!

It is the point where your earlier decisions are locked in.

Taking the time to plan properly up front makes the rest of the renovation much less stressful and avoids expensive changes later.