Monday 9 July 2018
In the rush to gain skills and abilities as a furniture designer and maker it is easy to forget that a successful business requires cash flow and profit to pay overheads, salaries, investment in business growth, holidays, sick days, advertising, non-billable labour, etc, and one key to profitability is accurate estimating.
The estimating procedure relies on setting a time allowance for a job, item or process followed by discounting for multiples of that item. Pricing uses a 5 per cent charge reduction for each job or unit repetition up to a maximum of 30 per cent. A unit is a process, job, square foot, square metre, etc.
Techniques not detailed here should be added along with a time allowance allocated according to your records, with times modified to accord with your own experience.
Computerised spreadsheets like Excel or Intuit's QuickBooks Pro handle long strings of number easily and work in imperial or metric, can convert values in one system to another and will perform all sorts of useful functions.
Timber and materials
Waste allowance varies according to species. Waney-edged boards are more wasteful than square-edged stock and timber with faults. It is also necessary to cut pieces about 100mm longer than required to allow for machining faults at the beginning and end of each board.
Estimate the rough-sawn requirement that will yield the finished dimensions. Waney-edged English oak has an additional waste factor of about 100 per cent, walnut 50 per cent, cherry 30 per cent and poplar 20 per cent. All materials are charged at cost plus a mark up of 25 per cent or more. With sundries like glues, screws and sandpaper work out the cost of direct expenses then charge indirect expenses at 10 per cent of direct expenses, not forgetting to calculate for VAT.
The materials mark up allows for wastage, saw doctor services, storage, machinery maintenance and tooling and timber delivery costs.
For initial machining of solid timber charge 28.25 hours per cubic metre. For board materials charge 20 minutes per sheet.
Carcass & frame joinery
Estimate joints in a carcass, frame or structure at two hours per joint. For every repetition give a discount of 5-30 per cent. Estimate hand carcass dovetailing at two hours per 300mm length with any additional part of 300mm to count as 300mm, at a minimum charge of two hours. Similarly, price hand-cut secret mitre dovetailing or secret lap dovetailing at 2.5 hours per 300mm length or part length.
Double-twisted dovetailing takes six hours for a 300mm length or part length.
Charge 2.5 hours to machine dovetail all four corners of a single large carcass – greater than 350mm – using a router and jig. Charge each additional carcass at one hour each with no discounts.
When estimating for moulding allow for three separate stages by router or spindle moulder comprising setup time, running the moulding and preparing the moulding for polish.
With carved and compound moulding which usually requires patterns, jigs or fixtures with special safety hold-downs, these additional elements must be accounted for. Because once patterns are made they are reusable, the full cost of making these jigs should only be charged to customers commissioning a one-off job.
Estimate the moulding portion of carved work as plain moulding. For hand carving charge two hours for each 300mm length of material up to 50mm wide, adding an hour for each additional 50mm.
Estimate hand-dovetailed drawers at eight hours per drawer. The charge includes time for making and installing a solid wood bottom which is fitted with slips moulded and joined to the drawer sides. Price lesser-quality drawers accordingly.
Estimate handles according to type and charge for cockbeads at half an hour per 300mm plus 0.5hr per scarf joint or corner mitre.
Estimate drawer front mouldings as above plus half an hour per joint and 30 minutes each for installing 300mm lengths as with cockbeads.
Discount in 5 per cent increments up to 30 per cent.
To set up and cut one machine-dovetailed or finger-jointed drawer box, charge 1.5 hours, after which charge one hour per drawer.
Estimate at four hours per door for hanging and fitting, including notching out and attaching brass butt hinges and locks. Handles and pulls should be charged as for drawer handles.
Cost out glazed doors with wooden tracery at two hours per glass pane in addition to door-frame joinery.
For rail-and-stile joinery using matched cutters with an inverted router or spindle moulder, allow 1.5 hours to cover setup, test fitting and running the mouldings, increasing the charge for additional rails, mullions or muntins. Charge one hour for each additional door with no reductions for multiples.
Bending and veneering
As a base rate charge every square foot at eight hours, then apply discounts from 5-30 per cent.
These times don't make adjustments for such factors as the complexity of the mould or former that must be made, the method of bending, number of laminates or preparation time.
For jobs of 0.6sq m or above calculate at 60hr per M2 which includes the maximum 30 per cent discount.
Estimate a veneering job at 1.5 hours per 300mm square, discounting at 5 per cent per additional square foot. Reduce charges if using a guillotine and joint-stitching equipment. Anything over 0.6m square can be calculated in whole metres and attracts a 30 per cent discount.
Veneer work for very large projects such as conference tables, custom-built cabinetry and wall panelling is often best subcontracted to specialists.
Crossbanding and inlaid lines are charged at 0.5 hours per 300mm length at above-quote discounts. Charge 30 minutes per joint. For leather and baize tops estimate as for veneering.
Framed backs using full mortice and tenons should be charged as before. For installation of backs charge two hours, to include an allowance for working grooves or rebate in carcass sides and top. Estimate at one hour per shelf for fitting and fixing.
Allow 1 hour per top for attaching to carcasses and table frames. Where the top rails have to be cut out to accommodate a fixing plate allow two hours. If tops are attached with wooden buttons or traditionally formed pocket screws, allow 3.5 hours.
Using mostly hand methods, charge 5.5 hours per square metre or 0.5 hours per square foot. Preparing surfaces using power tools, charge 0.75 hours per square metre or 15ft2 per hour.
For scraping and sanding mouldings up to 50mm wide, charge 30 minutes per lineal metre or one hour per lineal 6ft, ie 10 minutes per foot.
Charge at 0.75 hours per square metre or 15sq ft per hour to allow for mixing dyes or stains, raising the grain and sanding back if using water-based products, applying the colouring agent by spray gun, cloth or brush, wiping off and cleaning up.
Times given here apply to spray polishing of nitro-cellulose-type lacquers, oil varnishes, shellac etc. For French polishing and the like charge 30 minutes per coat per square metre or 30 minutes per 10sq ft.