Buildings in the US

[MortarThePoint]

I found the video below and interesting watch from a UK perspective. I'm not knocking it in any way, but it highlights the difference between UK building regulations and the US. It's worth noting that they build much larger homes in the US and are much more likely to have AC. There are also many more homes in the US. In the UK, we go a long way to make our houses perform more effectively in deference to the climate impact, but we all share one atmosphere and a single US home may have an impact 3-4 times as large as a UK one and there are probably 6 times as many. It's easy to start to doubt our approach in the UK, but worth keeping an eye on the personal financial impact as well as the environmental benefit.

 

As an example, at 13:28 they show the floor insulation which is US R10 and looks to be about 50mm of XPS. R10 in UK units is a U-value of 0.57 W/m²K. Air interfaces etc may lower that to something like 0.5 W/m²K, but the limiting value for building regulations in the UK is 0.18 W/m²K and the notional value is 0.13 W/m²K. Just considering that and the larger footprint area in the US makes a huge difference. Various Google searches suggest that the average footprint in the US is over twice that in the UK. If you assume the same weather, that means they pass about 6 times a much heat through the floor as a UK house. The roof and walls also wouldn't come close to meeting UK building regulations values and are of much greater area.

 

Are we over doing it in the UK?

    

 

[G and J]

I wonder how close to European building standards we are compared to US ones.  In my mind the EU is a comparable in size to the US.  
 

Energy has been cheap for a long time in the US and as the orange man-baby demonstrates a rather retro attitude to climate crisis is not unknown there.  So I’d be reticent about being guided by US standards.  
 

Having said that I wonder if the return in investment would be better if we mandate airtightness and MVHR rather than any more insulation, but I do wonder if such a reg change would prove ineffective in the face of peeps not maintaining their units.  We are a bunch of geeks on here really and regs have to work for the masses. 

[SteamyTea]

10 hours ago, MortarThePoint said:

If you assume the same weather

That is part of the issue, the weather regimes are very different.

[G and J]

So do US regs vary significantly by region?

[JohnMo]

5 minutes ago, G and J said:

So do US regs vary significantly by region?

Yep

[G and J]

Something about the US that makes sense.    Who’d have thought it?

[Oz07]

They have sensible energy prices unlike here. Even in Australia its not unheard of for them to have aircon in their garage or tool shed.

 

Another quirk i find they seem to be able to build a lot more custom things. It appears to me they can stick build with timber over there and as long as they follow local codes they're good to go. I feel like over here we need to involve a structural engineer for every thing unless its an approved detail.

[JohnMo]

13 minutes ago, Oz07 said:

appears to me they can stick build with timber over there

So can most areas of the world 

[SteamyTea]

16 minutes ago, Oz07 said:

stick build

 

1 minute ago, JohnMo said:

most areas of the world

 

A friend of mine is an American and she worked for a large architectural company.

She had never heard the sayings 'as safe as houses' and 'put your money into bricks and mortar'.

 

They do teardown and rebuild a lot more than we do, use fractures to produce structures, don't piss about on site, generally have a more relaxed view in planning, and I think the codes they work to are easier to understand.

 

As for the sizes of the houses, the UK has disgustingly small houses. We should be ashamed of our housing, and of the industry I  general.

[ProDave]

The US has very different climate to us, but lots of different climates in different areas.

 

I still remember well my first trip to the US, just outside Chicago in the middle of summer.  I could not believe how hot it was, their normal summer temperature we would be calling a heatwave and not coping.  Everywhere had air conditioning and we spent as little time as possible outside getting from one aircon building to another, in our aircon car.

 

Second visit was the same place in December.  I could not believe how cold it was, and how much snow there was.  But there were enough snow ploughs to cope.

 

So my take away from that, was the need for a lot of heating in winter, a lot of cooling in summer, and I suspect there is not much time in autumn fall and spring when it is a comfortable temperature.  I concluded that would be one of the very last places I would choose to go and live.

 

What little I have seen of typical US timber frame build is they are not as well built as what we do, and I am sure I remember they design for a 50 year life then tear down and rebuild.

[saveasteading]

Interesting points of view.

 

Timber houses is the standard in Scotland and whether kits or stick built makes little difference to the design.

I've got a how to do it book which is US and ultra practical,  but explains it all well and is common sense. We've worked to that for the principles and it sits on the Architect's desk.

The chippies know most, but not all, of the principles.

Bco walks past the work, presumably looking at some details and principles.

 

I've also got a very complex text book on designing in timber....I haven't looked in it for years, but let @Gus Potter and his ilk do the specialist stuff.

So, I say go for timber if you want.

 

Ludicrous energy prices? That's the only way the public will take notice. Yes it should be tweaked but that will happen over time.

Water is about £2/m3 if I remember. That's not enough to change habits which looks like being essential.

in Spain it is 70c.... ludicrous.

 

Me? I'd lower elec prices for the average essential use, then raise the tariff on an exponential. Thus hot tub,  swimming pool, aircon people pay much more.

Water similar.

 

In Spain 20 years ago there was no insulation in Med areas. Now it's  50mm or so.

Up in the cold north I expect, but don't know, that it is much more.

Scotland's insulation requirement is slightly greater than England's. But for av 3°C difference that makes sense.

[MortarThePoint]

The difference in average electricity price is a big contributor to the difference for sure. Gemini says that the average in the US is $0.18/kWh which works out as 13p/kWh. Gemini also thinks the average UK electricity price is 26p/kWh. So domestic electricity in the US is half the price it is in the UK. That's a major contributor to the difference in economics.

 

Drawing comparisons between the UK and US housing is complicated by the fact that the average age of US (42) houses is considerably less than that in the UK (63). In particular, a smaller proportion of UK (15%) houses were built since 2000 than in the US (28%). We're interested in new builds though, so the average UK new build house will be much better than the average UK house.
 

Energy generation in the UK is more environmentally friendly too, so it's a triple whammy: U-values, Area and CO2e/kWh.

• France: ~0.052 kg CO2e / kWh (52 g), heavily driven by nuclear energy.
• United Kingdom: ~0.129 to 0.207 kg CO2e / kWh (129–207 g), supported by high wind and low-carbon generation.
• United States: ~0.367 kg CO2e / kWh (367 g), combining natural gas, renewables, and remaining coal.
• Germany: ~0.380 kg CO2e / kWh (380 g), transitioning through a mix of renewables, gas, and coal.
• Poland: ~0.810 kg CO2e / kWh (810 g), remaining high due to a heavy reliance on coal.

 

[MortarThePoint]

2 hours ago, SteamyTea said:

That is part of the issue, the weather regimes are very different.

 

Agreed, but arguably they have more justification for insulation (maybe not in the floor) than we do given their AC use.

 

The US obviously doesn't use the same SAP system as us, but they have their own equivalents which look to be voluntary. The HERS index looks most useful an is an inverse scale where 100 represents a standard newly built US home in 2006 and 0 represents a Net Zero Energy home.

 

According to Gemini (summarise by me):

The UK Ministry of Defence maintains an overseas accommodation policy framework (JSP 464) that formally maps international energy metrics to the UK SAP/EPC bands for service personnel housing. According to their official conversion methodology:

• SAP 92–100+ (EPC Band A): Maps to a US HERS score of 0 to 12 (a near Net-Zero home).
• SAP 81–91 (EPC Band B): Maps to a US HERS score of 13–55 (highly efficient modern US builds).
• SAP 69–80 (EPC Band C): Maps to a US HERS score of 56–70 (average modern US energy-star builds).
• SAP 55–68 (EPC Band D): Maps to a US HERS score of 71–100.

Therefore, a US home hitting exactly HERS 100 sits right at the bottom edge of a UK EPC band D (or the upper edge of an E).

 

The US New Build Average (HERS 53): Squeezes into the SAP 76 to 81 range, EPC band C or just into B.

 

Fewer than 1% to 2% of all new-build homes in the US achieve a HERS Index score of 12 or less which is SAP 92 or higher.

 

That's a standard newly built US home has a SAP score of about 78 and EPC band C.

[-rick-]

I get the impression from watching builders on youtube that the variation between states is quite significant, with those states with higher and denser populations having much tighter rules and those states that have very cold winters having much tighter rules.

 

Still overall, Americans are well known for using vastly more energy per capita than other parts of the world. It's the typical result of very polarised politics. Democrat gets in and tries to get tighter rules. After big fight, watered down rules get put in then Republication gets in and undoes them (and even makes them worse than before). Thankfully a lot of rules are by the states, the federal ones are minimums that the states often exceed and the states have more stable politics (for good and bad).

[Oz07]

6 hours ago, saveasteading said:

Interesting points of view.

 

Timber houses is the standard in Scotland and whether kits or stick built makes little difference to the design.

I've got a how to do it book which is US and ultra practical,  but explains it all well and is common sense. We've worked to that for the principles and it sits on the Architect's desk.

The chippies know most, but not all, of the principles.

Bco walks past the work, presumably looking at some details and principles.

 

I've also got a very complex text book on designing in timber....I haven't looked in it for years, but let @Gus Potter and his ilk do the specialist stuff.

So, I say go for timber if you want.

 

Ludicrous energy prices? That's the only way the public will take notice. Yes it should be tweaked but that will happen over time.

Water is about £2/m3 if I remember. That's not enough to change habits which looks like being essential.

in Spain it is 70c.... ludicrous.

 

Me? I'd lower elec prices for the average essential use, then raise the tariff on an exponential. Thus hot tub,  swimming pool, aircon people pay much more.

Water similar.

 

In Spain 20 years ago there was no insulation in Med areas. Now it's  50mm or so.

Up in the cold north I expect, but don't know, that it is much more.

Scotland's insulation requirement is slightly greater than England's. But for av 3°C difference that makes sense.

Without wanting to get in to a slagging match why would you want to punish high energy users? Surely the attitude should be I want us as a country to produce as much energy, reliably and as cheaply as possible (plus cleanly if that bothers you). It just seems such a backwards way of thinking to me and feels like it's why we're in the position we are.

[saveasteading]

2 hours ago, Oz07 said:

why we're in the position we are.

All my fault.

I was just thinking we could turn the gas turbines off.

But don't you agree that is a way ahead for water?

[Oz07]

I just don't agree with charging high users more per unit. The price is the price. Why punish people for using more? Let's just focus on energy abundance. Improve the generation capacity. Same story with water really, increase supply or storage. Countries with reasonable energy prices can afford to desalinate. 

[JohnMo]

8 hours ago, MortarThePoint said:

US is $0.18/kWh which works out as 13p/kWh. Gemini also thinks the average UK electricity price is 26p/kWh.

Trouble with averages they don't really tell you that much - 26p is because nearly everyone is on a standard tariff. I live in the UK and currently pay 10p for all my electric at most, summer it's mostly free. Others pay less and many pay more.

 

3 hours ago, Oz07 said:

Thus hot tub

I have a hot tub always at 37 degs. Summer use is supplied via solar and battery, it's also heat pump heated, so uses very little electrical.

 

8 hours ago, MortarThePoint said:

United Kingdom: ~0.129 to 0.207 kg CO2e / kWh (129–207 g), supported by high wind and low-carbon generation.

But Scotland is 0.02kg CO2e / kWh and produces more than it can consume at lot of the time - not always. But I'm with @saveasteading charge high users, they are the ones that add an extra power station or result in a gas powered station being started. Generating more or providing more water so people can water the garden cheaply or build or live poorly insulated houses, why?

 

9 hours ago, MortarThePoint said:

France: ~0.052 kg CO2e / kWh (52 g), heavily driven by nuclear energy.

European countries are having to reduce output, because water is in short supply for cooling or just warmer than is helpful.

[Oz07]

@JohnMo did I mention hot tub or has something gone haywire with the forum?

 

Anyway I'm all for hot tub and aircon and whatever else people want to use energy for. Knock yourself out as far as I'm concerned would love to be sitting in a hot tub right now. 

[JohnMo]

44 minutes ago, Oz07 said:

@JohnMo did I mention hot tub or has something gone haywire with the forum?

@saveasteading did - not you, so no idea why it says you did - strange 

Edited 1 hour ago by JohnMo

[G and J]

I like the idea of a two tier pricing system for essentials like lecky and water.   
 

I guess for me the concept that everyone deserves a fair basic allowance at a reasonable price is a very good one.  
 

The idea that the wealthy can disregard the scarcity of resources, thus pushing up unit costs for other users, is an uncomfortable one.  
 

So we charge wasteful/profligate users more for their usage above their basic ration and that pays for the required top up infrastructure rather than charging everyone for it.  Goodness knows how such a pricing system would work but I’d vote for that.

[Mike]

1 hour ago, G and J said:

So we charge wasteful/profligate users more for their usage above their basic ration and that pays for the required top up infrastructure rather than charging everyone for it.  Goodness knows how such a pricing system would work but I’d vote for that.

As of a couple of years ago, all local authorities in France have the powers to implement variable pricing schemes for water & sewerage if they wish. Unlike the UK, most of the water & sewerage infrastructure is municipally owned (though private companies are often given time-limited concessions to operate the networks). Some areas do nothing, some have progressive rates according to the m³ used, some have a 'free' allowance included with the standing charge then a m³ price above that, some pay subsidies for large families, etc.

 

For electricity the most progressive feature is that the standing charge varies according to the Ampage you subscribe for (so UK-style 100A connections are rare). You also get to choose from over 50 providers, or EDF's regulated tariff (similar to the UK price cap).

 

Not sure about variations in gas pricing (I had mine disconnected). For all fuels, those on modest incomes get sent an annual subsidy cheque to spend with their chosen provider too.

 

Edited 32 minutes ago by Mike