[michieldotv]

Quite expensive? That's understated. My understanding now is that it comes at the cost a modest new house.

Our family bought a house in the immediate periphery of a smaller city. Since most city housing here is old, the consequence of that decision is that our modest city home has abysmal energy efficiency.

I have wanted to renovate ever since we bought it, in order to cut down on our carbon footprint before 2030, but I have given up on the idea that we'll be able to afford a heat pump before then.

After having spoken with several architects, the building cost alone will eat up €200K without any frills. This will make our house smaller, by replacing poorly built annexes with a more compact and thus thermally efficient cube shaped annex. This comes on top of the mortgage that we took out.

So ironically, in making our home more energy efficient, we would also be making it smaller and less desirable in this regard, at a great expense. Tacking on a heat pump and PV panels would inflate the cost by another 10%.

That is the very real cost of making a home suitable for low energy heating systems.

Don't get me wrong, I'm counting my lucky stars that I'm able to consider such an undertaking, but going through this exercise myself is just a reality check of how dire the situation really is.

If we want to achieve net zero in housing, can we really do so at the cost of conventional building practices?

Talking about the local situation, less than a third of homes are from after 1981 [1]. That's millions of homes slated for a similarly-priced revamp. Who is going to foot the bill? Even with government incentives, some owners don't want to spend all that money on something as intangible as low energy housing, and others simply can't afford to.

[1] https://statbel.fgov.be/en/themes/housing/building-stock

[alkonaut]

What is it that would make it so expensive? (edit: ah you meant the renovation not the heating system) A good heat pump for a large house is sub €10k. Of course you need some way of distributing the heat in the building too (water radiators or in floor heating). Is it that the houses completely lack radiators? Retrofitting a heat pump to a home that has a water radiator system and with fossil burning boiler is cheap.

I’m replacing my 20 year old heat pump now with a new one and it’s around €8k installed. At the same time I’ll tear out the floors and radiators (replacing the floor anyway) and replace with heated floors. This costs at least another €20k but isn’t really necessary - that’s just a luxury when changing the floors anyway.

Good thing around here really old houses have 200mm insulation and newer ones have 300+ required by the code. Regulation also bans fossil heating or direct electric for any new construction or major rebuild.

[michieldotv]

> What is it that would make it so expensive?

I know €200K sounds like a lot, but if you strip out unavoidable costs such as VAT, architect's fees, misc hidden fees, what you are left with is a whole lot less.

Let's say they account for 20% of your project cost, that leaves you with 160.000 EUR to buy materials and pay craftsmen.

> Good thing around here really old houses have 200mm insulation and newer ones have 300+ required by the code. Regulation also bans fossil heating or direct electric for any new construction or major rebuild.

Where is that?

Laissez faire was the norm until the 90s here. Urban planning, zoning, and building codes might have theoretically existed before, but enforcement was nonexistent. Energy efficiency regulations are newer still.

As a result, insulation in most homes from before 1990 is severely lacking (if not entirely absent).

> At the same time I’ll tear out the floors and radiators (replacing the floor anyway) and replace with heated floors. This costs at least another €20k but isn’t really necessary - that’s just a luxury when changing the floors anyway.

So, to give you an example: I'll also install heated floors since they are the most suitable heat delivery system for heat pumps and so the most future proof, but first I'll have to excavate 55 cm so I can fill it back up with insulation mostly so as not to lose all of the heat to the bare soil.

[adrianN]

For old houses were retrofitting is not possible, a district heat network can help. But yes, housing is really hard to get to net-zero. What I don't understand is why it's still legal to build new houses with fossil fuel heating.

[michieldotv]

Talking about Belgium, 40.000 additional homes are being connected to the gas grid every year (2020/2021). That's astounding.

We stopped mandating new connections. Great. Insidiously, though, Big Gas successfully lobbied for a price cap of 250 EUR for new connections to the gas grid.

So not only are we still allowing new housing to be heated with gas, we're saying that that's a-ok you can do it on the cheap.

It's almost as if politicians actively want their voters to feel disenfranchised. Who's going to tell those households in a few years that, "Whoops we made a mistake--so maybe this natural gas thing for heating wasn't such a good idea after all"?

At the same time, households who are leading the charge in the energy transition with heat pumps pay full cost, get no rebates, and, cherry on top, pay through the nose for per kWh surcharges on electricity that don't exist for natural gas.