smart51

I'm sure you know. WC improves the CoP of the heat pump by reducing the flow temperature in mild weather. I'm slowly setting up my WC curve. Typically, the weather has warmed up. I could do with a couple of cold days to do further tests. I'm setting the WC curve to be a balance between the house sitting at the desired temperature by lowering the flow temp, and our wish for it to be cooler over night and then warm up in the morning. I've found that setting the flow temperature that would give an equilibrium temperature of 22° allows the rooms to warm from 18° to 20° in a reasonable time. The limitation is I can only set one WC curve. The living room has huge solar gain and is always a degree or two warmer than everywhere else. Even if I had the flow temperature lower, the stat in the living room would turn on and off.

UFH heat up time is a good point. I've been running tests with the WC curves to see what the flow temperature needs to be in different weathers. I've found that it takes 1.5 to 2 hours to get from 18° overnight to 20° (depending on the outside temperature and the WC curve. It then crawls up at about 0.3° per hour. Even with a 0.5° hysteresis, the cycle time would be several hours.

I've just had an ASHP fitted with under floor heating downstairs and radiators down stairs. I also have Heatmiser neoStats for each zone. The neoStat has a user selectable hysteresis, which can be set to 0.5°, 1°, 2° and either 3° or 4°. The default is 1°. What would be more efficient for the heat pump? The heat pump has a weather compensation curve, so it turns down the flow temperature if it is warm outside. Even so, the thermostats will turn on and off. With the stat set to 21°, the heating will turn off when this is reached and will turn back on when the temperature drops by the 0.5° or 1° hysteresis setting. A smaller hysteresis will have the zone switch on or off more often and for shorter durations. A bigger hysteresis will have each zone on for longer, then off for longer. Part of me thinks that a 0.5° hysteresis would allow the thermostats to be set to 20.5° instead of 21°, which would save some power. I wonder which would give a better CoP. What do you think?

We now have permission to build a rear extension. 20m2, nothing special. I've asked two for quotes so far, both said they're too busy. Can you recommend someone around the SW of Birmingham who will do a good job?

When I worked for an engineering design consultancy, my time was charged out at £400 a day. With inflation, call it £450. I was in the wrong field, obviously.

I've just had a quote from a surveyor to value a plot of land I'm considering valuing. They said £800 + VAT which surprised me. I didn't think that much work was involved. I asked for a valuation both as is and with planning permission for a single house. Their reply was that as the land currently has a scout hut on it, that it is planning category F which they cannot value. But they would be willing to provide a 'residual valuation' the land on the assumption that residential planning was granted. They suggested that the land may have more value under its current planning category. Given all this, I'm surprised at the quote. What would a land valuation usually cost?

No

The site used to house a church. It was demolished after an arson attack. One of the questions I've asked (but not had a reply) is if the foundations were removed or just covered over

I've just spoken with an adviser from Potton, a firm that offer self build services. Their opinion is that the land is valued as if it has planning permission. They thought that the price should be for sale around £50k without planning, perhaps with an Overage clause. One suggestion they made was that we could ask for a conditional contract. One where both sides agree to sell the land for the agreed price if planning is granted but agree not to sell the land if planning is rejected. He said that might be difficult with a sealed bid sale and a fixed date. I asked about getting pre-application advice from the council which he said would be a good guide, but we might not get a reply before the sealed bid date. He also suggested paying for an independent valuation both with and without PP.

Not quite. Having seen estate agents value houses I wonder how much knowledge and skill they apply. The last one we used seemed to look on Rightmove for the highest price anything had sold on our street, added 10% then round it up to the next £10k. We had several offers equal to the highest previous price on our street. The estate agents valuation was just fantasy. Back to the matter in hand, You had the land valued on the day PP was granted, where does the 20 years come in? Is it the case that you only have to pay the overage if you sell within the 20 year period?

Are you sure about the base value? I read it as a percentage of the 'increase above the purchase price' i.e. not on the base value, just the increase. I will check with a lawyer of course. On the rest of it, a surveyor can value the land both with and without PP? I'm struggling with that. The value of goods only being what someone will pay, valuation is a guess. I don't think I like the guess of their surveyor.

I think it worth giving a few more details. It is a suburban site that once housed two buildings. The larger of them was demolished over 20 years ago. The smaller building remains. We would build a house and I would keep the current building as a workshop. The site was split in two a little over 20 years ago. The other part was given planning permission and 6 bungalows were built on it.

£100/m2 but a lot of m2. It is almost the same price as the surrounding houses.

I know what you mean, but... We've been looking for a plot in the area for years. One has been to auction twice but withdrawn the day before both times over disputes over ownership. One was a tiny patch of car park between a shop and a prison. The other was a triangular scrap of land between the back of a hospital and the railway line. I'd like to make it work, but I wonder if it is adding up to too much trouble.

I'm not sure what you're saying. We are looking at a plot which is for sale with an advertised guide price. The firm of surveyors handing the sale has sent us a form where we make our offer together with any due diligence conditions that our offer may be based on. They sent us to a link to some documents which include site plans. The plot is advertised on Rightmove and that's where I found the brochure. Buried in that is the Overage statement. We want the site to build a single house for ourselves. You could fit 8 terraced houses on it at a push. What would the seller state when applying for outline planning permission? It is a less than ideal situation. I'd like to navigate through it as best as possible.