Before you start this project first inspect the condition of all the surfaces to be painted. Look closely at the condition of the exterior walls for any signs of mould. If any is detected during your inspection mix a solution of 1 part bleach to 6 parts water and apply to affected area. Now leave this solution to dry then using a wire brush remove the debris.
If any of the exterior walls have loose or powdery surfaces they again need to be cleaned and sealed. Use a primer solution to seal all affected areas this will act as a stabilizer for your first coat of paint.
Using paint rollers can be the quickest method to cover most exterior surfaces, although you may need to use a brush to cover heavy areas of pebbledash. By attaching an extension handle to your roller this will enable you to tackle most of the paint-work from the ground. One method is to start rolling at the top right corner of your first wall, if you are left handed start at the left side first. Now gradually work your way across the wall until completed.