Hire a project manager from the start, says Isabel Morton

IT IS SO easy to get carried away with the excitement of it all. Your architect has drawn up superb plans, your neighbours have not complained, the planners gave you permission, the bank gave you a few bob, the builder miraculously arrived as scheduled and you have a big yellow skip outside your door.

You are planning colour schemes, sourcing furnishings and have pencilled in a party to celebrate the completion of your glamorous new home. It will be transformed into a haven of warmth and good taste. Your friends will be green with envy and glossy interior magazines will be fighting to feature your kitchen extension and witty downstairs loo.

You have spent months researching and viewing houses and attended every exhibition in any way related to interiors, building and DIY. You have set up your design office in the corner of your kitchen and have collected files of magazine cuttings, brochures, interior books, fabric samples and colour cards.

You now feel confident that you can act as project manager on your own building job. Your architect said that he was too busy to supervise the job on a day-to-day basis, and the money saved will leave you more to spend on the interior. It may even be the start of a new career for you.

Everything progresses nicely while they are pulling down walls and clearing rubble. However, things start to go wrong when the foundations are poured for the extension. Suddenly you realise that your new kitchen will not be quite so big and bright after all. You call the architect, he talks to the builder. The measurements are correct, as per the drawings.

From that moment on, things go from bad to worse. Site meetings become contentious. You can't follow all the abbreviations. RSJ is easy, but what are DPCs and RFIs? The builder starts mumbling about how architects should spend less time in college and more time on site. The plumber walks off the job because you decided (rather late in the day) that you wanted an American fridge which requires a water supply. You discover that the radiators have been installed in the most ludicrous places and the lightfitting in the atrium is so high that it will need scaffolding to change the bulb.

Nobody ordered the new windows and patio doors which take 12 weeks to be made, plus an extra two, because of the builders holiday. It pours with rain the week the roofers arrive. The plasterer's mother dies. The electrician ran off with his neighbour's wife and is now wiring houses in Australia.

You have delayed the decorator twice and he is now painting the railings in the Phoenix Park, so you won't get him again until 2020. And both the architect and the builder blame you for almost everything, because you are, after all, the project manager.

By week 13 you realise that the deadline date of 16 weeks to completion will not be met. In fact, you will be lucky if the job is finished by Christmas. The builder is now not speaking to the architect and wants all instructions in writing, in triplicate. The architect has threatened you regarding the number of changes you keep making to the plans. Your children are wearing hard hats and high visibility jackets to bed and your husband has started to play an excessive amount of golf. And, as you are both client and project manager, you are never too sure which hat you are wearing, but neither fit.

Save yourself, and indeed everyone else on site, the grief by hiring a project manager from the outset. Project managers come from a number of different backgrounds including architecture, engineering, quantity surveying and interior design. Your architect will put you in contact with someone who is experienced in this area. They should be introduced to the job at a very early stage, prior to the architects plans being submitted for planning permission.

A good project manager will interpret the drawings for you and guide you through the design and building process. They will keep an eye on costs, take notes at site meetings, produce contact reports which will include "action" lists, ensure that all building materials are on site prior to being required, and assist you in sourcing flooring, sanitary wear, kitchen units, etc.

As project managers are used to building site language, schedules and politics, they will be able to brief the architect on your requirements, act on your behalf when negotiating with the builder and advise you, should you be making incorrect design decisions. But most importantly, they will save you time, money and stress.

Leaving you plenty of time to plan your party, with your architect and builder at the top of your guest list.