Planning the build
Why build an extension?
Initial design sketches
On-line Building Regs
Meeting planners
 Meeting building control
 Planning the foundations
 Planning the floor slab
 Marking out the footings
 Damp proof course issues
 Possible drainage problems?

 Construction of the walls
 Proposed roof structure
Windows diary
 Window challenges
 Initial window plans
 Making the casements
 Making the frame
 Designing leaded lights
 Making leaded lights
 Assembling the window
 The little window

 The door frame
Demolition diary
 The demolition starts!
 The demolition continues
 Still more demolition

Foundations diary
 Foundation issues
 Drain issues
 Digging the foundations
 Rethinking foundations!
 Pouring the foundations

Floor slab diary
 Rethinking the slab!
 Floor vent extensions
 Preparing the slab #1
 Preparing the slab #2
 Pouring the slab

Walls diary
 Preparing to build walls
 Build up to the DPC
 Build the walls #1
 Build the walls #2
 The gas men cometh
 Build the walls #3
 Finishing the walls
Roof diary
 Roof structure build
 Tiling the roof
 Finishing the roof
 Finishing the gables
 Roof insulation

 Floor screed
 Shower room
 Shower room floors
 Shower room walls
 Utility room
 Utility room walls
 Utility room floor
 Finishing the windows

Project finished!
 Final inspection
 The certificate
 Final thoughts

 Twelve months on!
 Material costs
Sister sites
 House re-roof project
 Home gas usage data

 Stop paint flaking
 DIY secondary glazing


My initial window plans

As mentioned earlier, I have made quite a few windows for my house before, so I did not consider this as a too significant challenge. I would expect most people would go and find a local carpenter to make the window for them.

I won't provide too detailed plans on this site as I would expect other extension builders will want to match the style of windows in their own house. However, I will show how the windows were built.

I needed plans because I need to check that what I intend to build will meet planning regulation requirements. Interesting, it looks to me that all the regulations apply to the glass - there doesn't seem to be anything about how the opening windows fit into the frames to reduce possible drafts.

The inside view of the new triple window

The main window frame is made from 69 x 94mm planed softwood and the sill built from 140 x 60mm oak - hence the different colour on the drawing.

The outside view of the new triple window

The window is effectively triple glazed with the outside pane being a hand-made lead light window to match the rest of the house. The two outside windows can be opened with the middle pane being fixed.

Close up of the Windows frame with the windows in place

The individual window frames.

Three of these windows are required and are made from 44 x 69mm planed soft wood.

Close up of the frame

This shows how the individual parts of the window fit together and showing how the argon-filled double glazing glass can be removed to be cleaned by removing four strips of wood.

An exploded view of the window frame from the inside

The individual components of the window can be seen here - from the back:

  • The hand made lead light window

  • The 14 or 22mm thick double glazed unit separated from the lead light by 12mm

  • Four strips of wood screwed to the frame to hold the double glazing unit in place.

A close up of the window frame from the outside

This picture shows how the lead light widow fits into the frame - no putty is shown...

An exploded view of the window frame from the outside

The lead light windows fits into a 12 x 6mm slot around the edge of the window.

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