Light. You need it and regardless how many LEDs you fit, nothing can replace natural light. If you are not careful and don't consider it at the outset, barges can be places of darkness which have you blinking like a mole when you come out from your simulated subterranean lair. You can always close curtains/blinds but if you have not got enough windows it is likely you will be suffering from a Vitamin D deficiency and cowering in the corner mumbling "My precioussssssss" in no time at all.

It doesn't take much to flood the barge with light and make it seem larger than it is. Too much dark wood can have the opposite effect as in the image on the right.

Fortunately, we have already got 6 x 18" portholes for the living area, but this is definitely not going to be enough. My beloved has been badgering me for more light and, to be honest, she is totally right to do so. Fortunately we have a fairly large roof area which we can dedicate some to large rooflights and some to power production. I won't bore you with the exact details, but after much toing and froing with measurements, PV panel sizes I have worked out that I can get 8x280W domestic panels on the roof as well as 2 x double glazed vents (which also act as emergency exits) and 2 large (1.4m x 1.5m) flat double glazed rooflights. We had the choice of how to orientate them and decided that staggering the skylights would probably look a bit weird and screw with our collective OCD, so now it was just a question of where to put the big skylights.

At the opposite end to the main mast support would be the bathroom (approx 2m wide) so not really a high priority for light and then the kitchen area and after that the main living area which finishes just after the 2 smaller skylights. By biasing the skylights towards the bow (near the main mast stay) we felt one end of the living area would be very bright but we would suffer a bit in the kitchen area, so we compromised and have decided (currently) to put them in the middle.

There will be some tweaking of sizes of the main and minor rooflights as there are 2 flues to incorporate into the roofline as well. One from the pellet burner and one from the wood burner. It may seem overkill to have 2 sources of heat in the living area, but in my usual belt/braces/gaffa tape type paranoia about things breaking/running out of fuel etc the wood burner will be used really as a stand in for the pellet burner if we end up without fuel or we just want a real fire one evening. The benefit of incorporating a heat recovery system into the barge is that should the central heating be unserviceable for whatever reason, we can fire up the woodburner and heat recovery system will transmit the heat throughout the barge, meaning we will not have the scenario we had in our last boat where the saloon was roasting hot and the bedrooms were cool to cold at best...

So the decision has been made (subject to change obviously) to have the following orientation of PV and skylights.

The skylights themselves have been a struggle. I had seen several options for opening rooflights on gas struts which would have been ideal for allowing access to the main living area. For anyone who hasn't lived on a boat, you have to get everything into the living area through a very small door, or via a wheelhouse. Not handy when you are talking about an oven, fridge/freezer, pellet boiler, flooring,... well you get the idea. Having some form of large hatchway which doubles as a thermally broken and insulated skylight would seem to do the trick. But there was a catch...

And that catch was the price. Sweet merciful lord they are expensive... Most quotes for a couple of 1.5mx1.5m on gas struts or sliding were in the region of £7-8000. So, ditch that idea. No way I am spending what I got almost my entire power system and pellet burner for on a couple of windows. So engage grey matter and start thinking laterally...

Fixed double glazed units for 1.2m x 1.5m are around the £650 mark. Since we have the heat recovery system and the vents at the end of the living area, ventilation and emergency exits are taken care of. Really, all I needed was the ability to remove the skylight infrequently but to maintain its thermal properties and insulation.

Most fixed skylights are fitted to a builders kerb and screwed in place. We already have an angle of dangle on the roof so my idea was to have a steel kerb welded to the roof and then lined with wood. The wood is split so that half of it is attached to the roof and the other half is attached to the rooflight which can slot into place and be retained with some over centre clips on the inside.The metal kerb will keep the rain out, a neoprene/rubber seal between the 2 pieces of wood will be compressed by the over centre clips and provide a good seal and the clips on the inside will provide the security. If you need to get something large in or out of the main living area you can unlatch the clips, lift off the skylight from the outside and voila, you have access but at about 20% of the cost.

It will need to be carefully welded to ensure there is no warping or bending. I suspect I will have to make a sacrificial internal wood frame to keep the shape of the steel kerb while it is welded in place. Steel without any form of cross members etc can warp and bend when welded. It has to be welded in short, inch long sections and on opposite sides so as to keep the heat in the steel at a minimum. I will probably end up tacking the steel skirt to the steel, then welding it completely to the roof before plasma cutting the hole for the window, both to maintain the strength and also to allow better heat dissipation. I am planning to only fit one removable skylight opposite the flues as I think having 2 is probably excessive and I can almost guarantee I would knock one or both of the flues into the drink if I make the other side removable as well.

On the power side, there is another area of flat roofline above the 2 forward cabins which will each have a roof vent window in (for emergency exit and light) but will also have 3 x 280W PV panels installed. Along with 3 x 280W PV panels installed on the wheelhouse roof as well we have almost 4kW of PV. The wind turbine is going to require a little more headscratching to fit on one of the masts, but should provide a further 1kW of installed capacity.

Well, that's the plan anyway. The best laid plans of mice and men etc etc...