Does a variation entitle me to more time as well as money?

Usually yes, if the change actually delays the job. Under most contracts an instructed variation is a recognised ground for an extension of time, a formal moving of the contractual completion date to give you longer, and under NEC a compensation event deals with the extra time and money together in a single quotation. Time only follows, though, where the change affects the critical path, the chain of activities that fixes the overall finish date, rather than work that had slack around it. The trap is that on most contracts the money and the time run through separate procedures: valuing the variation does not automatically push the completion date back, and the extension of time claim usually has its own notice requirements and deadlines. Contractors routinely claim the money and forget the time, then face liquidated damages, the fixed sum the contract says you must pay for every day you finish late, at the end of a job the employer's own changes delayed. The remedy is simple: whenever a change touches the programme, say so expressly in the same notice that records the instruction, so both entitlements are protected from the start.

Say a main contractor building a school is instructed, six weeks before the planned finish, to add a whole new plant room, a change that sits squarely on the critical path because nothing else can complete until it is done. The contractor prices the extra work, gets the valuation agreed, and is pleased with the money. What it forgets is the time: the completion date never moves, because valuing the variation does not shift it, and the extension of time claim had its own notice and deadline that went unused. So the job finishes four weeks late, and the employer deducts liquidated damages, the fixed daily sum for late completion, of say £2,000 a day, wiping out most of the gain on the variation for a delay the employer's own instruction caused. Had the contractor written, in the same notice that recorded the plant room instruction, that the change would delay completion and an extension of time was sought, both the money and the time would have been on the table together. Claiming one without the other is a costly habit.