Normally, a Construction Contract might give an Owner control of the Design and Documentation and allow purchasing of certain specified materials delivered to the site, but the General Contractor would have full control of the Work including Means & Methods and Safety. It is possible to add a clause to the Contract for the Owner's Forces but it should clearly stipulate what Work that would be for, how it would be scheduled and coordinated, and how the liability and insurance would be divided. The other major concern (as others have mentioned) is that removing Work from the Contract reduces the GC's income and in most contracts the GC is allowed to retain the OH&P (markup) if it was not specifically excluded. However, contractors are finding it difficult to keep their forces busy much less make a profit so it may be wise to negotiate with your favored contractor early rather than bidding the project. It's difficult to beat a low markup on a Cost of the Work contract if you can supply some of the materials. But be careful about what you supply because the quality of internet materials is generally lower than what an architect would specify and the installer/GC would have no responsibility for failure and it opens up the possibility that the manufacturer and installer will blame each other for a failure and you will be left holding the bag. So, it is often wiser to let the GC supply the materials at a reduced markup. I am finding that many will forgo any markup for costs over an Allowance so low allowance values can work in your favor (if you anticipate the inevitable cost overruns in your contingency budget). But I find that the lowest cost method is a Cost of the Work with a Fixed Fee and a 50/50 Shared Savings (with or without a Guaranteed Maximum Price) because it most closely aligns the interests of the Owner and the GC (something that is completely missing in most projects whether you realize it or not). But that usually requires a very knowledgeable GC willing to do the paper work and an experienced Owner, Consultant, or architect to monitor it.

I would make sure that the evaporator is the same size as the outdoor unit. Being that the manufactured home is only 1200 sq.ft., i would tend to think it might be smaller than 4 tons. I am assuming since you said the evaporator was clean & new looking that you should also be able to see the data plate on it. Somewhere in the model # you should see a 48, ex: MDD48DSD is a standard 4 ton Man. Housing coil. If the nunber is smaller, say a 42 (3.5 ton) or even a 36 (3 ton), the you need to get a coil that is matched to the outdoor unit. If the home is pretty new (with in 10 years) the blower assembly will have the ability to deliver a full 4 tons of air. Thats usually how they come from the factory. Makes it easier on the installers. So... if the trailer is 1600 sq.ft., the it gets a 4 ton condenser & coil and hi spd. on the indoor blower. If its a 1000 sq.ft. home, it get a 2.5 ton condenser & coil and blower get set at medium low. Definitely check to make sure the coil and condenser are the same size. Hope this helps

I've heard there are online programs. You need to know your house construction pretty well to get an accurate calculation. Below is an example of how one exterior wall would be rated. Then you also figure windows and doors after that. Walls: (Each exterior wall, on each floor, must be done individually) Any windows and doors in a wall must be included with that particular wall. A rough drawing of each wall can be supplied, if easier, showing windows and doors. All measurements, in feet and inches for walls, windows, and doors, must be included for the length, width, or height. What direction does the wall face? O North O Northeast O Northwest O East O East Northeast O East Southeast O West O West Northwest O West Southwest O South O Southeast O Southwest O A: Wood frame, with sheathing, siding or brick Wall cavity O None O R-11 3 ½" O R-13 4" O R-19 5 ½" O R-27 7 ½" O R-30 8 ½" O R-33 9-10" Select exterior insulation O None O R-1.3 ½" Asphalt board O R-1.8 ½" Beadboard O R-2.5 ½" Extruded poly board O R-2.7 ¾" Beadboard O R-3.6 1 in. Beadboard O R-3.8 ¾" Extruded poly board O R-5.0 1" Extruded poly board O R-8 Sheathing O B: Masonry, above grade Select insulation value O R-5 1" O R-11 3 ½" O R-19 5 ½" Wall construction  no added insulation O 8" or 12" block O 8" block and 4" brick O C: ICF Insulated concrete form, above grade Select ASTM R-value O R-12 to R-14 O R-14 to R-16 O R-16 to R-18 O R-18 to R-20 O R-20 to R-22 O R-22 to R-26 O R-26 to R-30 O R-30 to R-36 O D: SIP Structural Insulated Panels O 4 ½" panel O 6 ½" panel Exterior finish O Stuco or siding O Brick O Split logs on both sides O E: Logs Circle the log thickness: 6" 7" 8" 9" 10" 11" 12" O F: Block or brick, extends to 5 below grade Select insulation value O R-5 1" O R-11 3 ½" O R-19 5 ½" Wall construction  no added insulation O 8 or 12 inch block O G: Block or brick, extends over 5 below grade Select insulation value O R-5 1" O R-11 3 ½" O R-19 5 ½" Wall construction  no added insulation O 8 or 12 inch block O H: ICF, extends to 5 below grade Select ASTM R-value O R-12 to R-14 O R-14 to R-16 O R-16 to R-18 O R-18 to R-20 O R-20 to R-22 O R-22 to R-26 O R-26 to R-30 O R-30 to R-36 O I: ICF, extends over 5 below grade Select ASTM R-value O R-12 to R-14 O R-14 to R-16 O R-16 to R-18 O R-18 to R-20 O R-20 to R-22 O R-22 to R-26 O R-26 to R-30 O R-30 to R-36

Hey, I had my own "Blew the budget" thread. A very wise KF guru (Buehl) gave me this great advice: To decide what you can do to cut costs, I recommend asking yourself the following questions: (1) What is not that important to me and doesn't add functionality? [Candidate for elimination altogether] (2) What can I do at a later date? [Candidate for deferring until a later date] (3) What can't be done at a later date and I can't live without? [Candidate for keeping and doing now] I know that you are also asking about what you can do vs. paying for a contractor, but you may want to narrow down the list with this logic first. At least that will help you to prioritize. It sounds like you have found at least one candidate for "what can I do at a later date" with the backsplash. For me, my moldings as a cross between 1 and 2 (doesn't add functionality and can be done at a later date), so that was going to save me a lot of $. Once you have your prioritization, then maybe you could break the project into phases with the #3s in the first phase, #2s, then finally #1s - mixing in the parts that you think you can do yourself. Good luck - it's tough making these choices, and it often feels like an "all or nothing" proposition.