Re-purposing an excellent terrazzo patio.

[David Costelloe]

I have a three storey house (build 1963) with a first floor balcony, which is overhung by our roof. This means that the side walls of the house project 1.6m beyond the external glazing of the rear of the house, and the balcony forms a cover over part of the patio to the rear of the house.

Under the balcony at c. 180mm below house floor level is a very solid, impervious terrazzo patio, 57 years old and no signs of damage or issues.

I propose to place glazed doors at the end of the side walls to extend the ground floor, insulate the balcony, and integrate the relevant bit of the patio floor into the house.

My question is around "re-purposing" the external patio floor to become past of the internal floor of the house. Adding 100-120mm of standard insulation or less thickness of a vacuum insulating system (eg Kingspan OPTIM-R) (plus an additional DPM and screed) takes care of Part L building regs.

It seems pointless to cut the terrazzo then dig out perfectly good, solid structures.

Does anyone have any experience of the approach I am proposing, how easy it was to navigate building control etc?

Are there any killer practical reasons for not adopting such an approach?

 

[noseall]

My question is around "re-purposing" the external patio floor to become past of the internal floor of the house. Adding 100-120mm of standard insulation or less thickness of a vacuum insulating system (eg Kingspan OPTIM-R) (plus an additional DPM and screed) takes care of Part L building regs.

It seems pointless to cut the terrazzo then dig out perfectly good, solid structures.

Are you talking about leaving the patio in place to serve as the hard core layer?

Essentially there is nothing wrong in doing this other than they will obviously be disturbed at the point where the new wall will be located. Also, their presence may be height limiting your floor detail or obstructing whether you need to run anything below ground beneath the patio layer. I'm guessing any slope on the patio will be rectified with the floor screed.

 

[David Costelloe]

Many thanks. I take your point - although I do not plan any new walling, as I will have full width sliding doors at the new structural opening ie between the sidewalls/pillar, so I need to consider what support I will need under the glazing frame. I suppose I can cut a strip into the terrazzo and excavate down