Nothing beats the satisfaction of a job well done by YOURSELF. These few extra tips may prove useful
1. Try and get used to measuring in millimetres (mm). There are 1000 mm in a metre. There are 25.4 mm in an inch. If you are at all uncertain about measuring in mm then give your measurements in both mm and inches. Your conservatory supplier should check both measurements given to make sure they match. (You may like to confirm this with them). If you are ordering a Bespoke Design then the conservatory supplier should send you an order acknowledgement - so you get an extra opportunity to check everything. When you get this acknowledgement do check it completely. Make sure all your instructions have been followed exactly.
2. Invest in a good quality (large blade) tape measure.
3. Never assume your house wall is plum. Using a line and weight, check your wall for plum (fix line to house wall at ridge level temporally and let weight hang at end of line at DPC (damp proof course) level). If the wall overhangs the base add this measurement to your base dimensions. For instance if you have an overhang of 20 mm and the base has a 3400 mm projection then you would make the overall base projection 3420 mm. The conservatory frames should still be manufactured to suit a 3400 mm projection and you will pack off/make good to conservatory frame.
4. The internal width of a conservatory frame/roof is external width less 200 mm and internal depth is external depth less 100 mm in all "normal" three sided lean to or Edwardian styles with no box gutters etc.
5. If you come across a problem or challenge which seems extra difficult - it is often a good idea to sleep on it. You know more than you think and given half a chance your brain will answer almost all your questions. Failing that - ask an Expert!