VOA - Publications - CTR(E) IA 111202 Data Quantity / Quality Audit

VOA - Publications - CTR(E) IA 111202 Data Quantity / Quality Audit - Property Attributes Data

CTR(E) IA 111202 - Data Quantity / Quality Audit - Property Attributes Data

These Instructions and Advice were prepared for internal use within the Valuation Office Agency as part of work towards a council tax revaluation in England that was due to take effect on 1 April 2007. The government announced its intention to postpone the revaluation on 20th September 2005 and preparatory work for a revaluation in 2007 has now been stopped.

1.	Introduction

1.1	One of the requirements of the recent council tax business review was to look at possible sources of property attribute data that could be used by a Computer Assisted Mass Appraisal (CAMA) system or Automated Valuation Model (AVM) that would assist with the 2007 Council Tax Revaluation in England.

1.2	While there are holders of property data relating to the English housing stock outside the VOA, in both the public and the private sectors, the VOA holds the most extensive set of property attribute data. Unfortunately the vast majority of this data is held on paper records.

1.3	In considering whether a mass data input exercise is something the VOA should proceed with, it is important to establish the quantity and quality of data that the VOA holds and whether this data could be used by a CAMA/AVM system to produce acceptable results.

	Groups in England are therefore required to undertake an audit of property attribute data.

1.4	The audit sample is made up of randomly selected addresses from all Billing Authorities in England in order to build up a national picture.

1.5	The property attribute data to be collected includes most of the current ten-box dwellinghouse (dwh) code data plus a number of other fields which staff have suggested would be useful to have and that are readily available.

2.	Methodology

2.1	Addresses that have live CT bands have been randomly selected from the central database (cdb) along with any dwh codes that are already held on the database.

	If a dwh code item already attached is found to be shown incorrectly because of, for example, being input wrongly to the cdb in the past, it should be corrected.

2.2	These addresses have been transferred to Excel spreadsheets. A separate spreadsheet exists for each Location within each Group.

2.3	The addresses have been ordered in street order within postal districts within towns. This order cannot be changed.

2.4	The spreadsheet needs to be output to hardcopy and enlarged to A3. This can then be endorsed with data collected from hardcopy office records. This document will then act as an input document at the end of the exercise.

2.5	It is considered more effective to endorse an input document in manuscript and then input from there. The alternative is to locate the source document, take it to a PC and input directly from the source document. However, the source documents are bulky and do not lend themselves to doubling as input documents.

2.6	Data will need to be collected from either surveys (CV/R/37s / VO9072s) or precis sheets. Surveys are considered the preferred source, as these are more likely to have been maintained. However it is known that when the initial coding exercise was undertaken in the 1970’s some offices only endorsed precis sheets with dwh codes and did not endorse the surveys. If this is the case, then the source for obtaining some property attribute data, particularly the group, type and age codes will be the precis sheets.

2.7	Under ideal circumstances a trawl of surveys for information is the first step followed by a trawl of precis sheets for any missing information.

2.8	Locations are required to acquire and input 12 pieces of property attribute data for each address. Data needs to be input by selecting an option from a drop-down menu that will include a ‘not known’ option for every field except heating which just has ‘Yes’ or ‘No’ options. No keying of data into the spreadsheet is permitted.

2.9	The drop-down menu method will ensure that no invalid codes are entered, thereby reducing the number of possible input errors.

2.10	Use of the ‘not known’ option will indicate that the data is unavailable. If the field was allowed to be left blank then that would indicate that the data was either unavailable, the operator had missed completing a field in error, or the entry should have been 0 (zero).

2.11	When data input has been completed, a check should be undertaken to ensure every field has been completed.

2.12	Finally, prior to informing CEO that the exercise is complete, a questionnaire is required to be completed that will provide information as to where data was collected from for each BA area.

2.13	Resource used on carrying out this audit must be recorded on the Activity Monitoring Return in the row titled "Council Tax Rebanding".

2.14	A checklist is provided at Appendix A as an aid to completing the task.

3.	Preparatory Action

3.1	Each location can locate their spreadsheet by accessing the ‘Council Tax Revaluation 2007’ folder on the ‘P’ (Public) Drive, and then a sub-folder entitled ‘Data Quality’. Do not move the file from this location.

3.2	The spreadsheet is large and takes a little time to open.

3.3	The spreadsheet opens at a ‘Guidance Notes’ worksheet. Notes 2 and 7 must be ignored as these are incorrect and superseded by instructions in this IA.

3.4	The addresses are sorted in the following order Town, Postal District, Street. Unfortunately this order can not be changed.

3.5	Groups should note that not all the information contained in the worksheet is visible, eg. BA Reference Numbers are available if required. Any request for more information to be displayed should be made to .

4.	Data Collection

4.1	The worksheet named ‘Data Input Sheet’ should be opened and printed by pressing the print icon.

4.2	The printed hardcopy should be enlarged by photocopying to A3 which will make it easier to be used to endorse with the property attribute data prior to input.

4.3	The data required to be collected and associated advice is contained in Appendix B. Appendix B can also be used as a training aid prior to commencing the task and the issues discussed with those collecting data.

4.4	If data is unavailable for any field, the input document should be endorsed NK as this will be required to be input to the spreadsheet.

	Do not leave any data fields blank on the input document.

5.	Data Input

5.1	When the data collection task has been completed, the spreadsheet must be opened and the worksheet named ‘Completeness Check’ accessed.

5.2	No input is allowed to this sheet but the word ‘OUTSTANDING’ in a cell indicates that the corresponding field has not been completed on the ‘Data Input Sheet’. Once input has been completed, there should be no cell containing ‘OUTSTANDING’ on this sheet.

5.3	The worksheet named ‘Data Input Sheet’ should be opened and the property attribute data that has been collected input to the appropriate fields against each address.

5.4	Data must be input by clicking on the down arrow in the appropriate field and selecting an option from the drop-down menu. This method has been used in order to ensure that no typing errors can be made.

5.5	An entry must be made in every field. In all fields except ‘Heating’ there is a ‘not known’ option and in the floors and floor level fields there is also a ‘not applicable’ option.

	The ‘not applicable’ option in the floors field should be used for all flats and maisonettes and the ‘not known’ option in the floor level field should be used for all houses and bungalows.

5.6	Once input to all fields against all addresses has been completed, the ‘Completeness Check’ worksheet should be accessed.

5.7	The sheet should be scrolled through and this should now be completely blank except for the column headings and address details. If there is a cell with an ‘OUTSTANDING’ entry, this indicates that that field has not been completed on the ‘Data Input Sheet’. The blank field must be completed before informing CEO that the exercise is complete.

6.	Completion of Questionnaire

6.1	The worksheet named ‘Data Source Questionnaire’ must be completed prior to the spreadsheet being returned to CEO. This will enable a picture to be built up of the nature of each BA and the source of data. It will also give an indication of the reason for any lack of data.

6.2	It should be completed by clicking onto the boxes which are applicable. There is space for general comment at the foot.

7.	Completion of task – by 10 January 2003

7.1	When it is confirmed that all fields have been input, in CEO must be emailed and informed that the spreadsheet is completed.

7.2	Hardcopy input documents must be retained on site for a limited period. The destruct policy will be the subject of future guidance.

Please click here for the Appendix A check list aid.

Appendix B

Data Collection Advice & Training Aid

Group

If the dwh Group code is not endorsed on survey sheets, then an attempt should be made to obtain it from precis sheets.

If the dwh Group code is not available on either document, then staff extracting this data are not expected to interpret data on surveys/precis sheets in order to allocate a code. The field on the hardcopy input document should be endorsed N/K.

Type

If the dwh Type code is not endorsed on survey sheets, then an attempt should be made to obtain it from precis sheets.

If the code is unavailable and surveys/precis sheets give a clear indication that the property is a house or bungalow and its ‘detachment’ is available, a code can be applied. If the code is unavailable and surveys/precis sheets give a clear indication that the property is a house or bungalow but its ‘detachment’ is unavailable, then code HZ or BZ should be used.Type codes in relation to flats and maisonettes are more difficult to determine and staff are not expected to determine these codes. Where codes are unavailable the input document should be endorsed N/K.

Area (m²)

The floor area should be available on survey or precis sheets. If older surveys are not endorsed with the area in the dwh code box, the area might be located in the main body of the survey. However, the only area available may be in square feet.

To convert square feet to square metres multiply the square feet by 0.093 or use the area converter on the Intranet in Business\Tools\Area Converter.

Where areas are unavailable the input document should be endorsed N/K.

Age

The age code required to be input to the spreadsheet is the alpha code as described in the dwh coding guidance on the Intranet.

It is likely that many age codes will be recorded on surveys and precis sheets in the former numeric format. These numeric codes will be required to be converted to the alpha codes.

A table is provided below to assist with the conversion.

If no age code is available, the year built may be recorded on the survey. However, some older surveys only indicate how old the property was when that inspection took place, eg. 40 years.

Groups should be aware that the age code contained in column 2 of precis sheets is not a dwh age code and must not be used.

Where codes are unavailable the input document should be endorsed N/K.

Dwellinghouse Coding - Age Codes

Dwellings are placed in age bands which are donated by a series of letters.

Year Built	Age Code	Former Age Code
Pre-1900	A	01
1900-1918	B	02
1919-1929	C	03
1930-1939	D	04
1940-1954	E	05
1955-1964	F	06
1965-1972	G	07
1973-1982	H	73,74, 75,76 etc
1983-1992	J
1993-1999	K
2000-2009	L
2010-2019	M

Parking

Parking codes can be found in the dwh coding guidance on the Intranet.

An extract of the advice in LT250402 is provided below.

"Triple (and larger) garages should be input as double garages (DG). Carport structures should not be included except for their "site". The "off-street" parking may include reference to a designated parking space in a parking lot nearby, the concreting-over of the front garden with vehicular access, or anything between. A garage "not within the curtilage" of the dwelling, but which nevertheless is in the same occupation or ownership as the dwelling and would be included in the sale price if the property were sold, should be reflected in the code."

Many older surveys and precis sheets do not provide as much detail about garages as is required for this exercise.

Ideally, surveys and precis sheets will be endorsed ‘single’, ‘double’ or ‘tandem’ – garage. However, very often surveys are just endorsed ‘garage’ and dimensions are provided.

To help with the determination of the type of garage some typical dimensions are provided below.

Single garage :-	2.75m x 5.50m	or	9 ft x 18 ft
Double garage :-	5.50m x 5.50m	or	18 ft x 18 ft
Tandem garage :-	2.75m x 10.50m	or	9 ft x 34 ft

Specific details about parking spaces are patchy.

If the survey mentions that the property has a carport or hard standing then the code FS (off-street parking) can be used.

Surveys are unlikely to provide much detail about on-street parking. If the survey does not record that there is a carport or hard standing and it gives no other detail about parking, then parking should be recorded as N/K.

Precis sheets may not record whether garages are single, double etc. Sizes may be available and local advice may be required to be given as to the old Gross Values attributable to each type of garage.

Heating

When the dwh codes held on the cdb were increased to ten in April 2002, the Heating code was defaulted to Yes (Y). Many older surveys and precis sheet entries will still indicate that there is no central heating at numerous properties. It can be safely assumed that in the majority of cases there will now be central heating installed in these properties.

Only where the survey has been recently amended and it specifically mentions that there is no central heating should N (No) be input. (Apologies are made for the fact that the Y default could not be transferred to the spreadsheet being used in this exercise).

Therefore, the data recorded for heating will always be Yes unless a recent inspection indicates that there is no heating.

Rooms

The instructions in the dwh coding guide on the Intranet should be followed:-

	include as rooms all living rooms, separate dining rooms, studios, bedrooms and boxrooms;
	exclude kitchens, utility rooms and bathrooms, and dining areas within other rooms.

Surveys will normally indicate the number of rooms in one of three ways:-

	old surveys	in a grid box system towards the top left of the form. Guidance may need to be given to those who are required to extract the information on how to extract the information from these boxes;
	mid age surveys	rooms will be named and listed either towards the top left hand corner or in the centre of the survey;
	new surveys	numbers of rooms will be provided in the boxes towards the bottom left of the survey.

If none of the above is available, then the plan may give an indication of the numbers of rooms.

Precis sheets will indicate the number of rooms in columns 6 to 8.

Where no details of accommodation are available, the input document should be endorsed N/K.

Bedrooms

This information is not currently collected as part of the ten-box coding system on the cdb. However, it is felt that this information is a value-significant item so this audit will look at the availability of this data.

Out of the total number recorded under ‘Rooms’ above, how many of these are recorded on surveys as being bedrooms.

For houses, if this information has to be gleaned from precis sheets, assume rooms on upper floor(s) are bedrooms. For all other types of dwelling where information is only available on précis sheets, eg. bungalows, flats etc, record N/K.

Bathrooms

The instructions in the dwh coding guide on the Intranet should be followed:-

	include as bathrooms en-suite facilities with at least three fitments;
	exclude all separate WCs.

Many older surveys will indicate that there are no bathroom facilities in the dwelling. In the majority of instances this is probably no longer the case, however no assumptions should be made.

If the rooms and bedrooms details are available and there is no mention of a bathroom, then 0 (zero) must be recorded.

If no rooms and bedrooms details are available and therefore those fields have been recorded as not known, then if bathroom details are also unavailable then N/K should be recorded.

Precis sheets provide bathroom details in column 10.

Number of Floors – Houses and Bungalows only

This information is not currently collected as part of the ten-box coding system on the cdb. However, in some locations second floors of houses and dormer bedrooms in bungalows have been included in the floor area at 2/3rds area. This information is therefore thought to be useful, if only that it alerts to the fact that the floor area may not be a ‘true’ area.

Surveys and precis sheets should indicate the number of floors in the same area of the documents from where the number of rooms is obtained.

This information is being sought for houses and bungalows only. Flats and maisonettes should be recorded as ‘not applicable’.

Where the number of floors is unavailable the input document should be endorsed N/K.

Floor Level – Flats and Maisonettes only

This information is not currently collected as part of the ten-box coding system on the cdb. However, in some locations this is thought to be a value-significant factor. In some areas, flats may decrease in value the higher in the block they are, in others they may increase in value the higher in the block they are.

Surveys and precis sheets should indicate the floor level in the same area of the documents from where the number of rooms is obtained.

The level on which the lower floor of the maisonette is situated should be recorded.

This information is being sought for flats and maisonettes only. Houses and bungalows should be recorded as ‘not applicable’.

Where floor levels are unavailable the input document should be endorsed N/K.

Modernisation

Only a few very recent surveys will carry a modernisation code that accords with the current dwh code system on the intranet. If it is there, record it.

Formerly, a letter may have replaced the ‘0’ of a former numeric age code. This will indicate that the property has been modernised.

If an	N replaces the 0 of the numeric age code, then use modernisation code	M1
If a	P replaces the 0 of the numeric age code, then use modernisation code	M1
If an	R replaces the 0 of the numeric age code, then use modernisation code	M2
If an	S replaces the 0 of the numeric age code, then use modernisation code	M2.

An M replacing the 0 of the numeric age code should be ignored. This is because this indicates modernisation carried out prior to 1980. In accordance with current coding guidance, this is to be ignored.

December 2002