Thermal transmittance

that they've pushed as much as they can push for the market to take in.

Yeah, and also it becomes a law of diminishing returns, isn't it? Once you get to the sort of levels of U-values, 0.15 for the walls, you have to remind me for the other elements.

0.13 for the floors, 1.1 for the

roof.

Well, it's

repeated, so it's repeated thermal bridging, i.e. per metre squared, it's the same of that metre squared of the wall to that metre squared of the wall.

Yeah, it's U-values, but

thermal bridging is linear metres, isn't it? Yeah, you could have

None of this is exotic.

It is the paperwork equivalent of asking a window manufacturer for a U-value.

The difference is that nobody expects to be refused the U-value.

The gap worth closing.

The standards exist.

So both the regulation and Approved Document L Volume 1 makes it clear that if a thermal upgrade would negatively impact on a building with historical architectural merits, then a lesser standard can be accepted.

So from an architectural perspective, from a principal designer perspective, it's a case of explaining we're not going to utilize the guidance within approved document L, which is table 4.3 relating to the U-value proposed.

Instead, we're going to utilize a lesser standard because of the architectural merits in these locations.

And therefore, rather than the approved document L, we would use an alternative standard.

So I just wanna share some of this with you, 'cause, uh, it applies wherever you are.

Now, if we have a look at the frame types, aluminum frames are common, but they're highly conductive, so they'll have higher U-values.

You can improve this through specifying a thermally broken aluminum frame.

That separates the inner and outer pieces of the frame, which reduces that conductivity.