Hi Guys,
Thanks to Jamie and Kevin for the replies, sorry about the delay getting back.
@ Kevin . Why would I multiply by 1150 ? ( I'm tired, lol )
I searched about for information on how to approach this as it is my first larger scale commercial contract than what I would normally be doing. Anyways , I'm happy to report that my end quote was excepted and I have scheduled the work for next Monday. I will probably make a video for upload at some stage in the future.
I thought I would share an example of the formula I went with in the end for those who may find it useful , Here it is...
Costing Based Pricing Structure
1. Calculate the hourly labor cost for the job.If you estimate that it will take two workers approximately three hours to complete the job, then the total work hours on the job is six hours. Next, multiply the total number of work hours by the hourly cost per worker (assume £10 per hour). Therefore, the labor cost for the job will be £60.
2. Account for fixed cost per hour, known as overhead. Vehicle and business insurance are a set amount each month. Other fixed costs include loan payments, rent and utilities. If your fixed expenses equal £5,000 per month and you have two full-time employees operating approximately 320 hours per month, then you would divide the £5,000 expense by 320 work hours to have £15.63 per hour of expenses. Therefore, multiply the 6 work hours for the job by £15.63 of expenses to come up with £93.78.
3. Add the cost of chemicals and other expendable supplies to complete the job. Assume the cost is about £10 in actually used cleaning agents.
4. Calculate the total cost of the job by adding your labor (£60), overhead cost (£93.78) and your variable cost (£10) to come up with your pre-profit figure of £163.78. Calculate in your profit by multiplying your mark-up rate, assume 25% by the pre-profit figure (£163.78) which is £40.95. Add the £40.95 to the £163.78 to get a final price of £204.73
I found this to be extremely helpful as it forced me to expand my thinking in how I have been doing business up to this point. ( one small job to the next one )

And again, thanks Jamie and Kevin for your input. a big help also.