Ste B
Sounds like you've not done this before ... what I did when I started was to charge per day. I reckoned on 1/2 day to remove old suite. Should take 2 hours but if you can't work out how to isolate the water then this is where the extra time might come in (e.g. turning off water, fitting new valves, etc.)
Perhaps 1/2 day for basin and 1/2 day for loo. If there's drainage to move then that will take longer, say another day depending on situation. Also, it's surprising how long it takes to go out shopping for bits and pieces you need. Finally another day for the bath.
That's 3 1/2 days for the plumbing. If it goes well, that's great but when you're new you hit all sorts of problems. Tiling is say 1 day then return the next day to grout and clean everything up (another 1/2 day).
All in all, about 5 days. If you say it'll take two days and you're nowhere near finished it puts too much pressure on you. If you say 5 days and only take 4 the customer will be much happier.
A good, experienced plumber swapping a like for like can charge £500 and fit all plumbing in one day. I'm not there yet ... so I tell the customer that I take care and make sure everything's fitting nice and squarely. And I fit according to the water regulations. And I'm clean and tidy .... etc. Likewise tiling. If you're not experienced, it takes longer.
Cost of labour, etc? All depends but take not of the cost of what you're fitting and match your labour charge accordingly. "A £500 basin will take much more care and attention .... blah, blah". If the customer is buying as cheap as possible, then you can't charge as much.
On the materials side, remember to charge for the consumables and not just the pipe fittings. Tile cement is expensive, and the silicone you used a few weeks ago will be useless so you need a new one. Ditto the Gripfill (or whatever glue you use). The last tube of glue I tried using was frozen! Also if you need wood you can't buy a small piece of sheet for a small price. Will the remaining cuts be usable in 6 months when you need it for another job? No? Charge for the whole sheet.
Cost to the customer? 5 days labour @ £150 per day plus £300 materials = £1,050. If the bathroom suite only costs £450 then this is where you have to be more careful with the labour costs. So if you only spend £75 on materials then you can drop the labour charge significantly and charge £150 for materials. Customers tend not to know how much materials cost so a profit on them helps offset reductions in labour.
Have you sorted out the rubbish? Hiring a skip ain't cheap and your council is unlikely to accept the waste if you take it there. That's something the customer has to sort out, albeit with some help from you.
Finally, before you leave, change your shoes and take 1/2 hour to clean everything including the floor and walls if necessary. And polish the taps and leave loo cleaner in the loo. It creates a great impression.
Good luck!!
Finally the boiler. If you can't find anything obvious and it looks okay, I'd suggest she finds someone to service/repair it. If she's never had it serviced, that's probably what it needs. Check the thermostats (hot water, room, radiator and boiler) are not set too low. If the house and water is cold and it only fires for around 1 minute it is probably the photocell. And if boiler engineer says she needs a new boiler, get a second opinion. If he says the same, then it would have to be changed.
