Extension sub-floor in block and beam or suspended floor

[loizos]

We are building an a 75 sq metre ground floor extension onto the back of a property (15 m wide by 5m coming out from the main house). A couple of rooms will be opened up to form an open plan kitchen, dining and living area.The existing house is 1906 construction using suspended timber floors. The architects have suggested block and beam / suspended floor due to proximity to trees and needing to dig 1.7m foundations. We would like to install underfloor heating throughout - for approx 45 sq metres of the existing house.

I'm not a builder but the builder is suggesting knocking through and ripping up the existing floors and putting block and beam throughout. This is an expensive option. I would like to know the best way to adjoin the two sub-floor types -- or even if it would be best in this case to just go with suspended timbers in the extension so it's consistent and use an underfloor product that is suited to that option.

Any thoughts or experience on the above would be appreciated! Thanks.

 

[loizos]

I should add that we plan to use water-based UFH. I am also curious how the builder would construct the floor if it is adjoining a suspended floor - and when they would do that in the project.

 

[noseall]

We are building an a 75 sq metre ground floor extension onto the back of a property (15 m wide by 5m coming out from the main house). A couple of rooms will be opened up to form an open plan kitchen, dining and living area.The existing house is 1906 construction using suspended timber floors. The architects have suggested block and beam / suspended floor due to proximity to trees and needing to dig 1.7m foundations. We would like to install underfloor heating throughout - for approx 45 sq metres of the existing house.

I'm not a builder but the builder is suggesting knocking through and ripping up the existing floors and putting block and beam throughout. This is an expensive option. I would like to know the best way to adjoin the two sub-floor types -- or even if it would be best in this case to just go with suspended timbers in the extension so it's consistent and use an underfloor product that is suited to that option.

Any thoughts or experience on the above would be appreciated! Thanks.

Sounds like a mare.

My experience of timber floor UFH is they assemble the water matrix on trays set between the joists, whilst the void below is packed out with insulation. Timber floor will be ok in the extension, but be aware you may need honey comb dwarf walls, depending on the span.