Can't you just board over them? NZ & French houses don't have exposed pipework, it's all in the walls as they have timber frame houses. I'd get a builder to build a timber framework and board over the top also boxing in the waste disposal. If you want acess to the waste disposal, you could make it look like a cupboard. Get a few quotes and see what the cost would be, it's probably less than you think.

As an experienced architectural designer my answer deals with your specific problems, but also contains general advice which could be useful to other readers, so please don't be offended or take what I write personally... I'm just trying to help people. I notice your house has a massive external surface area with which to lose heat, plus lots of windows so it will not be an easy house to keep warm! It would be very sensible to check out your whole house internally and externally with an infra-red thermometer as this will show up the worst heat loss spots. They could be around window frames, doors, skirting, ceilings and these are the places to target your heat loss fighting energy and finance. Your problem could be caused by a whole range of issues. Do you have a suspended timber floor which is ventilated? Just like your open chimney, the wind will rob any heat from the room unless you stop it doing so. This would involve insulating the floor in some way, and if you were taking up the floorboards you would be wise to treat the joists (especially the ends) and check for evidence of mice, which can play havoc in cavity wall insulation. Taking up the floor is a very disruptive job, which is why it has not been done in my house. Untreated timber could rot if ventilation is restricted by close-fitting insulation. If you have an unventilated floor, it may not have any or enough insulation. Also, beware of internal insulation as a solution, as this makes your outside walls colder/damper and usually leads to later problems with damp/mould/rot and expensive remedial work, even structural failure. Make sure you follow the advice of a competent person who understands how complex building physics can be. (Building services engineer). Bay windows are usually really poor bits of construction... If your double glazing has a large gap between the panes of around 20mm, it may not be the real problem. If the spacers (between the glass) are shiny aluminium, this is not good, so if you ever replace the glazing, don't settle for anything less than Edgetech Superspacer or Truplas, the very best warm edge spacers available. I live in a 1930's ex council house and I have blocked the only remaining chimney with a massive bag of loft insulation. The floor was already overlaid with a cheap laminate floor, so the floor gets cold when the winter winds roar. Reflective blinds (checkout Reflex Rol) can be used, but with a bay window, fitting will be complex and heat will still escape around the edges of the blind. Reflective foil is able to bounce radiant energy away from itself, but there should always be an airspace on each side of the foil or the energy just conducts through to the cold side. If the window faces south, then blinds could make the room even colder, unless you always remember to raise them early each morning - the same goes for thermal shutters. My house in Somerset has a gas combi boiler which has hardly needed to come on at all so far this winter. My gas and electricity comes from EBICO, as they have no standing charges. I have insulated the house externally with 50mm of Celotex, covered with treated battens and Marley Cedral weatherboard (which does not rot) and only adds around 80mm to the wall thickness, plus Cedral is perfect for eaves boards and soffits. (You can paint it whatever colour you like). This, plus a porch outside the front door has made a massive difference to my warmth as I am 70 and now live on my own. The attic has been properly insulated and boarded to become an unofficial room. I am lucky to have two unshaded windows that face south and they bring in lots of free energy. I am not stupid and I'm often in and out to my garden, so in winter I wear a vest under my T shirt, as well as a fleece and longjohns under my trousers (get them at Lidl) which is also a good place to buy LED lights. Always start with energy conservation and insulation rather than things that burn timber or fossils fuels and ignore the real problem. I would avoid burning wood, given the state our atmosphere and lungs are in. We are not cave men anymore and should be evolving. New energy efficient houses sometimes feature large south-facing PV roofs which directly heat a central water tank or can feed electric underfloor heated zones - and just like my 1970's experimental solar house, these super-insulated dwellings do not have a 'normal heating system'. I can't stand curtains, they look a mess, often block out solar radiation / light and have to be washed. I like close-fitting wooden floors which you can simply sweep with a brush and run over with an upright vac-cleaner. Tiles are a pain to keep clean and can break your hip as well as things you drop. We can save lots of money and energy by not buying things that need to be washed and dried, as well as things we really don't need!

Have you considered shutters? They give a real ‘wow’ factor and really make a feature of both rectangular and bay windows. You said your bay window looks out on the back garden. With shutters you can adjust the louvres to allow as little or as much ‘view-through’ into the garden. They would also give the privacy you need in a bedroom, as well as making the room dark enough for sleeping when the louvres are completely closed. You said you’re not changing the structural element of the room or the windows. By having shutters within the apertures, they would not get in the way of any cupboards or other modifications you might eventually make to the room. Another asset of shutters is that it doesn’t matter if windows are at different heights. Having the same product across all windows in a space creates a lovely considered and unified look. Also, when windows are above radiator (as in your square bay) and you have long curtains, you tend to lose heat behind the curtains. As shutters are insulating and fitted above the radiator, they can be used to reflect the radiator heat into your room. In a nutshell, shutters create a lovely aesthetic look in a room. You don’t need to dress the windows in any other way as they are a wow factor in their own right. Shades of white will make the room appear even larger. Alternatively, they can be colour-matched to your walls, flooring, bedding, etc. Yes, I have a passion for shutters! Joy

Yes, in fact we installed a box pelmet in the dining room to deal in fact with a problem with the coving not going over the architrave of the French doors. Unfortunately, by the time we realised a box pelmet would be a good idea in the living room, it was too late and the coving and architrave had all been done! That’s partly why we are thinking of a swags and tales solution. You can see this pelmet in a couple of the pictures I have attached. Unfortunately decorating is well underway now. You live and learn.