This month, Taunton Thespians staged an adaptation of Stella Gibbons' novel Cold Comfort Farm. Even if you haven't read the book, you probably know Ada Doom’s immortal line that she "saw something nasty in the woodshed".

Farmers could be forgiven for feeling as downbeat as Ada Doom when it comes to tax. Agricultural Buildings Allowances (ABAs) are being phased out, capital gains tax indexation relief has gone and HMRC increasingly challenge the inheritance tax relief for farmhouses. It is, therefore, essential to maximise the tax reliefs that still exist.

Most farmers are aware of the main reliefs: averaging of profits where one year shows a significantly different result to the next and offset of farming losses against other income for up to five successive years, for example. The withdrawal of ABAs seems particularly harsh, but there is in fact still potential to claim tax relief on some expenditure on agricultural buildings.

The key is to utilise the £50,000 annual investment allowance, to look for assets that would attract qualifying energy or water saving equipment allowances (at 100%), plant and machinery allowances (at 20%) or integral features allowances (at 10%). Most of us would know plant and machinery when we saw it, but integral features may be less obvious – unless you know what you are looking for. Broadly, the definition includes electrical, lighting and cold water systems within a building, space or water heating systems and ventilation systems. If you are having a new agricultural building constructed it may be worth putting your builder in touch with your accountant to ensure that all qualifying items are identified and claimed.

Time may be of the essence: the present government has changed the capital allowances rules radically several times and may do so again. The Conservatives have said that they may scrap the £50,000 annual investment allowance, reduce the 20% capital allowances rate to 12.5% and the 10% integral features rate to 6% to fund a lower company tax rate.

So would Ada Doom's descendants succeed in a claim for allowances on the woodshed? Well, there may be a chance if the shed can qualify as a temporary hut that can be moved from one site to another. And the same may be true of chicken shacks or poultry houses if they are not only moveable, but are actually moved. This is a complex area, however, and specialist advice is absolutely essential.

Paul Aplin OBE is a tax partner with A C Mole & Sons and a former chairman of the Institute of Chartered Accountants in England & Wales Tax Faculty. He can be contacted on 01823 624450, email paulaplin@acmole.co.uk. Bridgwater based tax partner Paul Kingdom can be contacted on 01278 446088, email paulkingdom@acmole.co.uk.